Physics Sketchpad – A Physics Simulator for Android
Physics Sketchpad is a free Android app that physics teachers may find useful. The app, which is still in beta, provides a simple interface creating simulations of the effects of global gravity on object and gravity between objects. The app also allows users to create collisions to view their effects on objects. The simulations that you create can be saved in your Physics Sketchpad notebooks. Sharing notebooks is a feature advertised for future development.
While Physics Sketchpad has a simple design, I still recommend going through all of the tutorials to really understand how it works.