The thesis describes the brief history of the Android operating system, as well as compares it to the other biggest mobile operating system iOS. I also described the different versions of Android, and the difference between them. After the theoretical part, I moved on to the practical part where I introdcued the programming of Android programs. Moreover, an application is introduced where I present the basics of Android programming. For this application I used Android Studio and Java programming language. The theme of the application is Covid, it is an informatory app about everything related to Covid for the population. The app includes information about Covid vaccines, Covid tests and other useful tips.