This app helps to remove the background of any picture of yours and maintain transparency with just a few taps. Just touch where you want to remove. 
◇  AutoCut: Auto Cut your photo.
◇  Erase: Erase the area you touched.
◇  UnErase: Restore the area you erase. 
◇  Flip: Flip the picture.
◇  Zoom In/Out: Erase the area more finely.
If you want to superimpose photos and make good composite photos. By using this app, you can do it better.