Cool examples:

Rotation of an image (Max)

Multiple frames (Max)

Pixel by Pixel Collision (Sadie, Megan) [notice the alpha value is 0 for transparent]

Images

Timer

Have only a few decimals:

  
  //with import java.text.*;
  
DecimalFormat df = new DecimalFormat("#.##");
        time.setText(df.format(elapsedTimeSec));