Dot Square is an interesting puzzle app game.  The object is to fill the empty circles with the correct colored ball.
  Two reds will crash into each other to form a single yellow.  Two yellows become a blue. Two blues become a purple. 2 purples become.....see for yourself.  All moves are swipes where everything travels until they hit an object.
There are 100 levels and each one must be completed within a given number of moves. I've noticed on multiple plays that certain levels were not possible only because the random reds that pop up after every move never appeared in certain corners.  Level 41 is one example.  But given enough replays, they're very do-able. Level 90 took me about 25 tries. Maybe even 50.
I've solved all 100 levels which is an indication of the addictive element and fun. But this is not a pure puzzle.

Definitely try this game.  If you know somebody who's hopelessly addicted to Candy Crush, this could help.
?
http://sharpapp.com/"ckattempt=1
https://itunes.apple.com/us/app/dot-square/id1104300777"mt=8

...