A mobile application is a common program that runs on mobile devices. This program is different from desktop and web applications due to the limited resources on mobile devices. Technically, we can develop any program on mobile devices depending on the device's capabilities. Designing UI and UX on mobile devices can also have an impact on the way the interfaces are implied.
Currently, there are two mainstream platforms in mobile application development: Android and iOS. Android is developed by Google, and iOS is developed by Apple. In this chapter, we won't focus on mobile development, but we will focus on how a mobile device can interact with an ESP32 board.