This study investigates the feasibility and functionality of accelerometer and gyroscope sensors for gesture-based interactions in mobile app user experience. The core of this innovative approach lies in introducing a dynamic and intuitive user interaction model with the device sensors. The Android app developed for this purpose has been created for its use in controlled experiments. Methodologically, it was created as a stand-alone tool to both capture quantitative (time, automatically captured) and qualitative (behavior, collected with post-task questionnaires) variables. The app’s setting features a set of modules with two levels each (randomized presentation applied, minimizing potential learning effects), allowing users to interact with both sensor-based and traditional touch-based scenarios. Preliminary results with 22 participants reveal that tasks involving sensor-based interactions tend to take longer to complete when compared to the traditional ones. Remarkably, many participants rated sensor-based interactions as a better option than touch-based interactions, as seen in the post-task questionnaires. This apparent discrepancy between objective completion times and subjective user perceptions requires a future in-depth exploration of factors influencing user experiences, including potential learning curves, cognitive load, and task complexity. This study contributes to the evolving landscape of mobile app user experience, emphasizing the benefits of considering the integration of device sensors (and gesture-based interactions) in common mobile usage.

With the rise of mobile devices and the high number of instant messaging applications available in the stores, it is necessary to evaluate the usability of such applications to provide a more satisfying user experience. To this end, this paper presents a methodical usability evaluation of instant messaging applications both in iOS and Android platforms. A predefined evaluation was used, which was created to detect the main usability issues of mobile applications, regardless of the device used and the evaluated applications. Consequently, two methods were used: the keystroke level model and the mobile heuristic evaluation. Also, the results suggest that the main problems of this type of applications are difficulties in performing tasks (some of them were not agile nor easy to complete), lack of element cohesion (some icons and buttons did not follow the style of the operating system, bad translations, and too much information on the screen), problems with the user interface (pop-ups overlapping the status bar, clipped elements, sometimes the interface did not rotate, and, in other cases, the interface changed considerably when the device was rotated), and lack of information about privacy and security features. Finally, based on the results, we propose a set of recommendations that will be helpful for developers of this kind of applications.

Nowadays, instant messaging applications (apps) are one of the most popular applications for mobile devices with millions of active users. However, mobile devices present hardware and software characteristics and limitations compared with personal computers. Hence, to address the usability issues of mobile apps, a specific methodology must be conducted. This paper shows the findings from a systematic analysis of these applications on iOS mobile platform that was conducted to identify some usability issues in mobile applications for instant messaging. The overall process includes a Keystroke-Level Modeling and a Mobile Heuristic Evaluation. In the same trend, we propose a set of guidelines for improving the usability of these apps. Based on our findings, this analysis will help in the future to create more effective mobile applications for instant messaging.