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The purpose of this study was to examine the validity of two wearable smartwatches (the Apple Watch 6 (AW) and the Galaxy Watch 4 (GW)) and smartphone applications (Apple Health for iPhone mobiles and Samsung Health for Android mobiles) for estimating step counts in daily life. A total of 104 healthy adults (36 AW, 25 GW, and 43 smartphone application users) were engaged in daily activities for 24 h while wearing an ActivPAL accelerometer on the thigh and a smartwatch on the wrist. The validities of the smartwatch and smartphone estimates of step counts were evaluated relative to criterion values obtained from an ActivPAL accelerometer. The strongest relationship between the ActivPAL accelerometer and the devices was found for the AW (r = 0.99, p < 0.001), followed by the GW (r = 0.82, p < 0.001), and the smartphone applications (r = 0.93, p < 0.001). For overall group comparisons, the MAPE (Mean Absolute Percentage Error) values (computed as the average absolute value of the group-level errors) were 6.4%, 10.5%, and 29.6% for the AW, GW, and smartphone applications, respectively. The results of the present study indicate that the AW and GW showed strong validity in measuring steps, while the smartphone applications did not provide reliable step counts in free-living conditions. [ABSTRACT FROM AUTHOR]

The article focuses on the controversy surrounding the Department of Justice's antitrust lawsuit against Apple, which has received both praise and criticism. Topics include the criticism of the DOJ's narrow definition of the relevant market as either "smartphones" or "performance smartphones," the significance of market definition in antitrust cases, and the implications of the DOJ's strategic choice in framing the lawsuit.

While subjective methods like the Yanagihara system and the House-Brackmann system are standard in evaluating facial paralysis, they are limited by intra- and inter-observer variability. Meanwhile, quantitative objective methods such as electroneurography and electromyography are time-consuming. Our aim was to introduce a swift, objective, and quantitative method for evaluating facial movements. We developed an application software (app) that utilizes the facial recognition functionality of the iPhone (Apple Inc., Cupertino, USA) for facial movement evaluation. This app leverages the phone's front camera, infrared radiation, and infrared camera to provide detailed three-dimensional facial topology. It quantitatively compares left and right facial movements by region and displays the movement ratio of the affected side to the opposite side. Evaluations using the app were conducted on both normal and facial palsy subjects and were compared with conventional methods. Our app provided an intuitive user experience, completing evaluations in under a minute, and thus proving practical for regular use. Its evaluation scores correlated highly with the Yanagihara system, the House-Brackmann system, and electromyography. Furthermore, the app outperformed conventional methods in assessing detailed facial movements. Our novel iPhone app offers a valuable tool for the comprehensive and efficient evaluation of facial palsy. [ABSTRACT FROM AUTHOR]

Background: 'Candidatus Phytoplasma mali', the causal agent of apple proliferation disease, exerts influence on its host plant through various effector proteins, including SAP11CaPm which interacts with different TEOSINTE BRANCHED1/ CYCLOIDEA/ PROLIFERATING CELL FACTOR 1 and 2 (TCP) transcription factors. This study examines the transcriptional response of the plant upon early expression of SAP11CaPm. For that purpose, leaves of Nicotiana occidentalis H.-M. Wheeler were Agrobacterium-infiltrated to induce transient expression of SAP11CaPm and changes in the transcriptome were recorded until 5 days post infiltration. Results: The RNA-seq analysis revealed that presence of SAP11CaPm in leaves leads to downregulation of genes involved in defense response and related to photosynthetic processes, while expression of genes involved in energy production was enhanced. Conclusions: The results indicate that early SAP11CaPm expression might be important for the colonization of the host plant since phytoplasmas lack many metabolic genes and are thus dependent on metabolites from their host plant. [ABSTRACT FROM AUTHOR]

In response to the COVID-19 pandemic, Apple Inc. switched its product launch from onsite events to pre-recorded online broadcasts. Yet this form has been carried on even though the pandemic has faded. It is unclear if this shift was accompanied by a move in language complexity and how the communication effect was influenced. This study analysed Apple's product launch events from 2016 to 2022 using quantitative linguistics metrics such as lexical complexity, word token length, entropy, readability, and sentence length distribution. The analysis adopted the reach-effect-durability framework for interpreting the effects of strategic communication. The results showed that Apple's online product launch events featured richer and longer words, increased text difficulty, and a decrease in the proportion of short sentences. Such changes happened in a balanced manner that can be interpreted in view of the driving and restraining forces resulting from the mode shift of the launch event. This study demonstrates the feasibility of assessing efforts and strategies used in a communication campaign through quantitative text analysis. [ABSTRACT FROM AUTHOR]

This paper builds on Khan's work on Amazon by transferring her normative framework to Apple. It explores the company's anti-competitive business practices, main antitrust concerns, and the currently proposed reform measures from an innovative business ethics and law (i.e., ordoliberal) perspective. The paper argues that one of the key issues with Apple is the company's closed ecosystem combined with its role as an internet gatekeeper. The E.U.'s Digital Markets Act, which aims to open Apple's ecosystem – via data portability, interoperability, and multi-homing requirements – is a necessary step in the right direction. Yet, it is insufficient to prevent the lock-in effects of a 'walled product garden' and ensure complete device and platform neutrality. That is, additional steps must be taken to overcome Apple's dual role as a platform operator and service provider and inhibit the company from engaging in anti-competitive business conduct. [ABSTRACT FROM AUTHOR]

Applications for the stock market that can be relied upon to provide the information regular and professional investors need to make better-informed purchases are a boon to both. A well-thought-out sales approach may help buyers mitigate risk, zero in on the companies most likely to provide the highest returns, and increase their chances of making a purchase. Due to numerous interrelationships between various company values, executing stock market research utilizing batch processing methods provides an exceptionally tough task. Technology advancements, such as the licensing of global processes, usher in a new age for stock market forecasting. The present market climate has increased the significance of data applications. An interesting and new contribution made by this work is the proposal of a deep learning-based resilience time series model for forecasting future market values. By analyzing financial time series, this study aimed to build a sophisticated strategy for forecasting stock market prices. The use of artificial intelligence (AI) to forecast future market behavior is one of the most intriguing developments in this generation of technological breakthroughs. Particularly promising results have been found when applying deep learning techniques to the task of predicting the actions of market players. In this paper, we propose a method for forecasting the final prices of publicly traded firms like Tesla, Inc. and Apple, Inc. by merging a convolutional neural network with long short-term memory (LSTM). These two methods were both developed with the help of deep learning techniques. The time frame covered by statistics used in these projections is two years. To evaluate the performance of our deep learning models, we compared their market predictions using several different metrics, including mean squared error (MSE), root mean squared error (RMSE), normalized root mean squared error (NRMSE), and Pearson's R. When compared to the options, the CNN-LSTM deep learning algorithm did the best. When comparing convolution neural networks CNN-LSTM model to the normal LSTM and a simpler deep learning variant, the latter showed to be more effective at forecasting stock market values. This was the case when examining all three variants together. [ABSTRACT FROM AUTHOR]

From a documentary historical perspective, the commercial expansion of telecommunications systems from first-world countries that have maintained a dominant presence in Mexico for 100 years is analyzed. The activated FM receiver in cell phones, which Apple has decided not to activate, serves as an example of the need to regulate the power of multinational corporations, which diminishes visibility in public communication and social media. Neither the public pressure from authorities, industry, and civil society in Mexico, Canada, nor the United States has succeeded in dissuading the iPhone from allowing such signals on its devices, thereby favoring the sales of headphones, music services, and mobile broadband data payments. Contributions from direct contact with media representatives and regulatory bodies are included. [ABSTRACT FROM AUTHOR]

In Epic Games, Inc. v. Apple Inc., the United States District Court for the Northern District of California held that Apple did not operate a monopoly in its App Store marketplace, offered through its famously known mobile device, the "iPhone." Both parties appealed aspects of the district court's decision to the Ninth Circuit Court of Appeals, which affirmed the decision in full, except for the award of attorney fees. While this App Store dilemma continues to unfold, several companies, U.S. states, and even the U.S. Congress have sided in favor of Epic, trying to provide support in its fight for a fairer App Store. This Note examines where the district court erred, and where it correctly applied the law. It also analyzes Epic's future chances, as there is a lot of work to be done before victory can be claimed. [ABSTRACT FROM AUTHOR]

With the current artificial intelligence (AI) boom, new innovative and accessible applications requiring minimal computer science expertise have been developed for discipline specific and mainstream purposes. Apple Intelligence, a new AI model developed by Apple, aims to enhance user experiences with new functionalities across many of its product offerings. Although designed for the everyday user, many of these advances have potential applications in neurosurgery. These include functionalities for writing, image generation, and upgraded integrations to the voice command assistant Siri. Future integrations may also include other Apple products such as the vision pro for preoperative and intraoperative applications. Considering the popularity of Apple products, particularly the iPhone, it is important to appraise this new technology and how it can be leveraged to enhance patient care, improve neurosurgical education, and facilitate more efficiency for the neurosurgeon. [ABSTRACT FROM AUTHOR]

Designers rely on sketching to visualize and refine their initial ideas, and virtual reality (VR) tools now facilitate sketching in immersive 3D environments. However, little research has been conducted on the differences in the visual and spatial processes involved in 3D versus 2D sketching and their effects on cognition. This study investigated potential differences in spatial and visual functions related to the use of 3D versus 2D sketching media by analyzing functional magnetic resonance imaging (fMRI) data. We recruited 20 healthy, right-handed students from the Department of Horticulture and Landscape Architecture with at least three years of experience in freehand landscape drawing. Using an Oculus Quest VR headset controller and a 12.9-inch iPad Pro with an Apple Pencil, we tested participants individually with 3D and 2D sketching, respectively. When comparing 2D and 3D sketches, our fMRI results revealed significant differences in the activation of several brain regions, including the right middle temporal gyrus, both sides of the parietal lobe, and the left middle occipital gyrus. We also compared different sketching conditions, such as lines, geometrical objects (cube), and naturalistic objects (perspective view of a tree), and found significant differences in the spatial and visual recognition of brain areas that support visual recognition, composition, and spatial perception. This finding suggests that 3D sketching environments, such as VR, may activate more visual–spatial functions during sketching compared to 2D environments. The result highlights the potential of immersive sketching environments for design-related processes and spatial thinking. [ABSTRACT FROM AUTHOR]

We study how Apple and independent repair service providers used different physical, regulatory, and digital instruments to influence each other's abilities to control the repair aftermarket of the Apple iPhone between 2007 and 2020. We show how the emergence of digital instruments for enacting control, made possible through emerging functionality for tethering, encryption, and temporary binding implemented in the iPhone itself, was shaped by and shaped the actions of Apple and the independent repair service providers, and led to a dominant tension between encrypted authorization and inscription of control through Apple and collective legal action by independent repair service providers. Our analysis provides a more nuanced understanding of control enactment by highlighting the implications of using different mediums for exercising control, and we provide a new way to understand the dialectics involved in enacting control in digital product aftermarkets. Our study provides insights that can inform the regulation of digital product aftermarkets--in particular, the ongoing debate about rights-to-repair legislation. [ABSTRACT FROM AUTHOR]

Jumps in the paths of efficient asset prices have important economic implications. Motivated by the issue of testing for jumps based on noisy high‐frequency data, we develop a novel spot volatility estimator, which is obtained by minimizing the sum of some Huber loss functions, and use it as an ingredient for jump detection. This type of estimators is uniformly consistent in estimating the spot volatilities of the efficient price at numerous time points. We further demonstrate the consistency of the proposed jump test based on the property of the novel spot volatility estimator. We show that in finite samples, the proposed volatility estimator and the test perform favorably compared to some competitors through Monte Carlo simulations. We also illustrate our methodology with the stock prices of Apple and Microsoft. [ABSTRACT FROM AUTHOR]

Background: The accuracy of human pose tracking using smartphone camera (2D-pose) to quantify shoulder range of motion (RoM) is not determined. Methods: Twenty healthy individuals were recruited and performed shoulder abduction, adduction, flexion, or extension, captured simultaneously using a smartphone-based human pose estimation algorithm (Apple's vision framework) and using a skin marker-based 3D motion capture system. Validity was assessed by comparing the 2D-pose outcomes against a well-established 3D motion capture protocol. In addition, the impact of iPhone positioning was investigated using three smartphones in multiple vertical and horizontal positions. The relationship and validity were analysed using linear mixed models and Bland-Altman analysis. Results: We found that 2D-pose-based shoulder RoM was consistent with 3D motion capture (linear mixed model: R2 > 0.93) but was somewhat overestimated by the smartphone. Differences were dependent on shoulder movement type and RoM amplitude, with adduction the worst performer among all tested movements. All motion types were described using linear equations. Correction methods are provided to correct potential out-of-plane shoulder movements. Conclusions: Shoulder RoM estimated using a smartphone camera is consistent with 3D motion-capture-derived RoM; however, differences between the systems were observed and are likely explained by differences in thoracic frame definitions. [ABSTRACT FROM AUTHOR]

This study investigates the complex interplay between public sentiment, as captured through news titles and descriptions, and the stock prices of three major tech companies: Microsoft (MSFT), Tesla (TSLA), and Apple (AAPL). Leveraging advanced analytical methods including Pearson correlation, wavelet coherence, and regression analysis, this research probes the degree to which stock-price fluctuations can be attributed to the polarity of media sentiment. The methodology combines statistical techniques to assess sentiment's predictive power for stock opening and closing prices, while wavelet coherence analysis unveils the temporal dynamics of these relationships. The results demonstrate a significant correlation between sentiment polarity and stock prices, with description polarity affecting Microsoft's opening prices, title polarity influencing Tesla's opening prices, and a positive impact of title polarity on Apple's closing prices. However, Tesla's stock showed no significant coherence, indicating a potential divergence in how sentiment affects stock behavior across companies. The study highlights the importance of sentiment analysis in forecasting stock-market trends, revealing not only direct correlations but also lagged influences on stock prices. Despite its focus on large-cap tech firms, this research provides a foundational understanding of sentiment's financial implications, suggesting further investigation into smaller firms and other market sectors. [ABSTRACT FROM AUTHOR]

The objective of companies is to seek profitability to guarantee their survival. To do this, they want their brand to be recognized and differentiated. Apple is a paradigmatic case in this sense. It is currently the most valuable brand in the world. Through a theoretical framework, a case study and ad-hoc research, the perception of the value of the Apple brand among iPhone users is analyzed. The brand identity acts together with the main attributes of the product to shape in the minds of the users an experience that is perceived as unique and valuable. [ABSTRACT FROM AUTHOR]

The task of detecting a structural change in conditional quantiles of time series with time-varying volatilities is vital in the field of financial time series, especially risk management. Therefore, in this study, we aim to construct a change point test to detect a quantile change by hybridizing the cumulative sum of squares test with the support vector quantile regression. Compared to the test employing the standard quantile regression, this approach not only provides more robust property against a high degree of nonlinearity of time series but also exhibits better performance for the datasets contaminated with high-frequency noises, as demonstrated in our simulation study. It also has merits to provide more diverse interpretations and a deeper understanding of financial time series than the volatility change point test, as illustrated in a real data analysis of three financial indices, namely, S&P500, Nasdaq composite index, and the stock price of Apple Inc. [ABSTRACT FROM AUTHOR]

A Zero-drift GARCH (ZD-GARCH) model is recently proposed to study conditional and unconditional heteroskedasticity together. Despite its attractive statistical properties, our research demonstrates that the stability test based on this model fails when structural changes are present. To overcome this issue, we allow the Markov regime-switching (MRS) feature within the ZD-GARCH framework and propose an MRS-ZD-GARCH model. A revised stability estimator is further derived. The effectiveness of our proposed approach to test the stability with and without structural changes is evidenced via simulation studies. Using the empirical data of the S&P 500, NASDAQ and Apple returns, we show that the new model can also outperform the ZD-GARCH model in practice and provide more informative results. Therefore, the MRS-ZD-GARCH model could be a widely useful tool to study the stability of financial data and help address risk management issues in other contexts. [ABSTRACT FROM AUTHOR]

Rheumatoid arthritis (RA) is a fluctuating progressive disease requiring frequent symptom assessment for appropriate management. Continuous tracking using digital technologies may provide greater insights of a patient's experience. This prospective study assessed the feasibility, reliability, and clinical utility of using novel digital technologies to remotely monitor participants with RA. Participants with moderate to severe RA and non-RA controls were monitored continuously for 14 days using an iPhone with an integrated bespoke application and an Apple Watch. Participants completed patient-reported outcome measures and objective guided tests designed to assess disease-related impact on physical function. The study was completed by 28 participants with RA, 28 matched controls, and 2 unmatched controls. Completion rates for all assessments were > 97% and were reproducible over time. Several guided tests distinguished between RA and control cohorts (e.g., mean lie-to-stand time [seconds]: RA: 4.77, control: 3.25; P < 0.001). Participants with RA reporting greater stiffness, pain, and fatigue had worse guided test performances (e.g., wrist movement [P < 0.001] and sit-to-stand transition time [P = 0.009]) compared with those reporting lower stiffness, pain, and fatigue. This study demonstrates that digital technologies can be used in a well-controlled, remote clinical setting to assess the daily impact of RA. [ABSTRACT FROM AUTHOR]

Background: Foreign body ingestion (FBI) represents the most common cause of emergent gastrointestinal endoscopy in children. FBI's management can be quite challenging for physicians because of the variability of the clinical presentation, and the decision tree becomes even more intricate because of patient-specific variables that must be considered in the pediatric age range (e.g., age of patients and neuropsychiatric disorders) in addition to the mere characteristics of the foreign body. We present an application for smartphones designed for pediatricians and pediatric surgeons based on the latest guidelines from the official pediatric societies. The app aims to help physicians manage FBI quickly and properly in children. Materials and methods: The latest pediatric FBI management guidelines were reviewed and summarized. The flow chart we obtained guided the development of a smartphone application. A questionnaire was administered to all pediatric surgeon trainees at our institute to test the feasibility and helpfulness of the application. Results: An app for smartphones was obtained and shared for free on the Google Play Store and Apple Store. The app guides the physician step by step in the diagnostic process, analyzing all patient- and foreign body-specific characteristics. The app consultation ends with a suggestion of the most proper decision to make in terms of further radiological investigations and the indication and timing of endoscopy. A questionnaire administered to trainees proved the app to be useful and easy to use. Conclusion: We developed an app able to help pediatricians and pediatric surgeons manage FBI in children, providing standardized and updated recommendations in a smart and easily available way. [ABSTRACT FROM AUTHOR]

The global smartphone market is one of the most dynamically developing markets with high competition. The presence of high-tech products in the smartphone market forces companies to act more cautiously and strategically. The success of companies depends on their level of meeting the demands of smartphone users. To this end, this study aims to determine the factors that are affected by the smartphone preferences of individuals and the effect level of these factors on company strategies. For this purpose, in this study, a survey was conducted in the TRA2 Region located in the east of Turkey. The obtained data from the survey was evaluated using the CHAID algorithm. In the study, it was seen that smartphone users liked the Apple the most in terms of perceived service quality. In addition, it has been observed that the highest level of expectation in terms of expected service quality is concentrated on the Apple brand. On the other hand, the most preferred Xiaomi was found to have the lowest brand loyalty. [ABSTRACT FROM AUTHOR]

In the contemporary American technology landscape, companies such as Apple, Amazon, Google, Meta, and Microsoft exercise unparalleled influence by offering ostensibly "gratis" services. This Article interrogates the veracity of this "free" paradigm, contending that consumers engage in a de facto quid pro quo by tendering personal data. We critically examine the application of the consumer welfare standard in antitrust jurisprudence, a standard that has enabled such corporations to amass significant market power without triggering traditional antitrust scrutiny. Courts have abstained from applying extant antitrust principles to these firms, largely due to an overreliance on consumer price as the litmus test for competitive harm under the consumer welfare standard. We posit that this misapplication perpetuates market concentration, thereby inhibiting innovation and disproportionately impacting vulnerable consumer demographics and small enterprises. To rectify this interpretive misstep, we advocate for the reconceptualization of data as a currency. Such a doctrinal shift would ameliorate the prevailing incongruities in the application of the consumer welfare standard, furnishing regulatory agencies and state Attorney Generals with a more nuanced metric for antitrust and consumer protection enforcement. The Article is segmented into four sections: (1) a reconceptualization of "free services" in the digital age, (2) an empirical analysis of burgeoning market concentration and its concomitant impact on technological innovation, (3) a historical exegesis of the consumer welfare standard's integration into antitrust law, and (4) a critique of the standard's role in diminishing consumer welfare. We conclude by proffering a suite of methodological frameworks designed to recalibrate the assessment of consumer welfare and market competition in technology sectors. This reevaluation is pivotal for the invigoration of competition and innovation within the American tech industry. [ABSTRACT FROM AUTHOR]

This article examines how the smartphone contributes to the co-production of security through an analysis of Covid-19 contact-tracing apps. Building on existing research in security studies that mobilizes the science and technology concept of co-production, the article proposes the notion of 'appropriation' as a concrete way of extending our understanding of the public/private co-production of security. Appropriation highlights how consumer technology may be repurposed for security and shows how private-sector actors that own consumer technology not only influence, but actively condition the co-production of security. Bringing new, typically commercial, concerns to bear on security practices, appropriation also has the effect of complicating conventional understandings of the relationship between liberty and security. Focusing on the NHS Covid-19 app and its contentious relationship with Google/Apple's framework for digital contact-tracing, the article demonstrates how the smartphone enables private-sector actors to gain influence in the security domain. Google and Apple used their control over smartphone technology to compel the British health authorities to adopt a less effective but more privacy-preserving approach than they originally intended, and thus enforced a seemingly liberal response to an exceptional political situation. [ABSTRACT FROM AUTHOR]

Background: Menopause can significantly hasten bone loss. Mobile phones provide an efficient way to manage, track and understand menopause using apps. A previous review of menopause apps found numerous apps designed to help women manage menopause. However, it did not use validated measures to assess the quality of the apps and did not focus on content related to osteoporosis. Methods: This app review aligns with the updated Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. The keywords used to search for the apps were "menopause" and "menopausal". Apps were included if they were in English, for individuals or groups and had a lifestyle focus. Apps that looked at other aspects of women's health, required external devices, cost to download, or were symptom-tracking were excluded. The quality and functionality were assessed using the Mobile App Rating Scale and IMS Institute for Healthcare Informatics Functionality score. Data were synthesised descriptively. Results: Twenty-eight apps were selected and reviewed from the 236 apps screened from the Apple store and Google play store. Only 57% of the apps reviewed (n = 16) had content on osteoporosis which was educational in purpose. The readability of the apps was complex and best understood by university graduates. The average functionality score of the apps reviewed was 4.57 out of 11 and that of quality is 3.1 out of 5, both of which need improvement. Conclusions: Existing menopause apps need more input from experts to improve the quality and functionality, using simple language. More emphasis on specific health problems during menopause, including osteoporosis, is required. Trial registration: Not relevant. [ABSTRACT FROM AUTHOR]

Portable depth sensing using time-of-flight LiDAR principles is available on iPhone 13 Pro and similar Apple mobile devices. This study sought to characterize the LiDAR sensing system for measuring full-field vibrations to support modal analysis. A vibrating target was employed to identify the limits and quality of the sensor in terms of noise, frequency, and range, and the results were compared to a laser displacement transducer. In addition, properties such as phone-to-target distance and lighting conditions were investigated. It was determined that the optimal phone-to-target distance range is between 0.30 m and 2.00 m. Despite an indicated sampling frequency equal to the 60 Hz framerate of the RGB camera, the LiDAR depth map sampling rate is actually 15 Hz, limiting the utility of this sensor for vibration measurement and presenting challenges if the depth map time series is not downsampled to 15 Hz before further processing. Depth maps were processed with Stochastic Subspace Identification in a Monte Carlo manner for stochastic modal parameter identification of a flexible steel cantilever. Despite significant noise and distortion, the natural frequencies were identified with an average difference of 1.9% in comparison to the laser displacement transducer data, and high-resolution mode shapes including uncertainty ranges were obtained and compared to an analytical solution counterpart. Our findings indicate that mobile LiDAR measurements can be a powerful tool in modal identification if used in combination with prior knowledge of the structural system. The technology has significant potential for applications in structural health monitoring and diagnostics, particularly where non-contact vibration sensing is useful, such as in flexible scaled laboratory models or field scenarios where access to place physical sensors is challenging. [ABSTRACT FROM AUTHOR]

A mobile navigation application (App) can provide flexible wayfinding guidance, save time, and reduce stress for people in unfamiliar buildings or environments. Wayfinding is also a challenging task for individuals with disabilities. The objective of this study was to provide a comprehensive set of guidelines for designing navigation apps for individuals with disabilities. A review of the literature was conducted on scientific studies and commercially available navigation apps using Web of Science, Compendex, ACM Digital Library, IEEE Xplore, Wiley Online, Science Direct, SpringerLink, Taylor & Francis, Apple store, and Google Play. The findings led to 82 design guidelines categorized based on Nielsen's usability principles. The guidelines were implemented in an interface prototype to help users navigate places within a shopping mall. The prototype demonstrated that the proposed design guidelines are easily applicable and provided a roadmap for the future design of navigation apps for people with different types of disabilities. [ABSTRACT FROM AUTHOR]

Hypercompetitive mobile app stores are characterized by rapid innovation and intense competition. App firms must vie for temporary competitive advantage through competitive actions such as releasing product improvements. We study how competitive indicators influence a particular competitive action--app updates--in a mobile game app market. Our results reveal that app firms take action to improve or sustain their temporary competitive advantage, updating their apps when there are opportunities to capitalize on popularity (e.g., rank and rating volume are increasing) and when their apps' advantages are threatened (e.g., customer ratings are decreasing). We also find that app updates are released in response to competitors' actions--specifically, when competitors update their apps and new competitors enter ranking lists. Moreover, our findings show that app firms release app updates when an app's customer rating volume is increasing or when an app firm's portfolio of game apps is less diverse, relative to its competitors. We conduct additional analyses that show that older app firms are responsive to more competitive indicators than younger ones and major updates are primarily used to respond to serious threats to apps' competitive positions. Overall, our results indicate that app updates are competitive actions used to improve or sustain temporary advantage when competitive indicators reveal opportunities to improve or threats to apps' competitive positions. [ABSTRACT FROM AUTHOR]