In the game MoleMash, a mole pops up at random positions on a playing field, and the player scores points by hitting the mole before it jumps away. This tutorial shows how to build MoleMash as an example of a simple game that uses animation.
Get this app on your phone by scanning the QR code below.
If you need a QR code scanner, download ZXing from the Android market on your phone.
Make your own custom version of this app by downloading the source and modifying in App Inventor.
download the zip file but don't unzip.Then in App Inventor choose More Actions | Upload Source
tutorial its Chapter 3 in the AI book. It provides step-by-step instructions for building the app.