This is MIT app inventor and is the same place I have been working on an app with multible app inside of it.

Click here to go to MIT app inventor

These are the blocks of code I used for one of my apps called paint pot

My freind and I are creating an app called a dream project and is is going to be a game were you can play against each other on the same device and try to score on each other. There will be at least 2 different modes.