Throughout the entire day, we are carrying or wearing one or more personal devices, such as smartphone, smartwatch, smartband, activity tracker, or smart ring. On the one hand, these devices provide an extraordinary source of information. They can collect health parameters, such as heart rate and blood pressure, and measure the activity of the user, for example, by counting the number of steps, track position, and speed of the user. On the other hand, the interface of these personal devices is designed to recognize the user’s actions and respond to them. A natural communication is established with the user, by means of touch, gestures, voice, and sounds. In particular, disruptive advances are expected on touchless interaction, such as the sensing technology developed in the Project Soli by Google. Furthermore, these personal devices can be aware of the usage context, for example, by automatically recognizing the activity performed by the user. Their behavior can be proactive: by recording previous routine and needs of the user, they can propose specific suggestions related to the current context, so anticipating the explicit user input.

New applications of personal devices are arising in many fields, such as health, wellness, and entertainment. At the same time, the service can be personalized and adaptive because the continuous flow of collected data simplifies the knowledge of the user and the understanding of routine changes. This special issue invites high-quality contributions to emerging applications of personal devices with intuitive user interaction. In addition, comprehensive review papers are also welcome. Submitted papers should outline the context of use in the abstract.

Potential topics include but are not limited to the following:

• Technological focus: ubiquitous computing, wearable technology, or body area networks
• Task focus: eHealth/mHealth, health risk assessment, athletic performance measuring, accessible walking, prevention of age-dependent diseases, or smart monitoring
• Environment focus: indoor/outdoor, home automation, smart cities, augmented reality, virtual reality, or gaming
• User focus: sport people, the elderly, able-bodied people, disabled people, or children