Jelly Fits Puzzle: free puzzle game app for iphone, ipad

Jelly Fits Puzzle comes from Qmax, Inc in China.  The object is to slide the colored tiles onto their homes.

Look at challenge level 24: see the small blue square? When the normal blue square gets to its home (which is covered up temporarily by the long vertical red rectangle), then the small blue square will disappear and turn white. Which means that pieces may travel over it.

There are 36 levels. I've done them all. Not terribly hard, but there's potential here.