Catrobat is a mobile visual programming system. Catroid is an IDE and Catrobat interpreter for Android. Paintroid is an associated paint program for Android that, among others, allows setting parts of images to transparent. IDEs and interpreters for iOS, Windows Phone, and HTML5 browsers are in alpha stage. There are more than 30 subprojects, e.g., allowing to enter musical notation by singing into the mike, or to program a Parrot AR.Drone. We use Test-Driven Development along with other agile methods, ensuring a clear and 100% up-to-date documentation.