A mobile visual programming system for Android smartphones and tablets

Catroid is a free and open source visual programming system that allows casual and first-time users starting from age eight to develop their own animations and games solely using their Android phones or tablets. Catroid also allows wireless control of external hardware such as Lego Mindstorms robots via Bluetooth, Bluetooth Arduino boards, as well as Parrot's popular AR.Drone quadcopters via Wi-Fi. The project is inspired by Scratch, supported by Google, so far has 170 active developers, is composed of more than 30 sub-projects (e.g., a subproject dealing with music composition using audio input sung by users into the microphone), and is growing rapidly. The visual language itself has been renamed to “Catrobat” as non-Android specific versions are under development. Current state (6/2012) of the Catroid system is open beta.