Folding Blocks by Popcore GmbH FREE

Folding Blocks comes from Popcore GmbH. The object is to unfold individual squares to form rectangles to eventually completely cover the grid.  It's not hard.  I've done about 30 levels out of 200. 

This game is reminiscent of Rect Pushers from 2015. If you find this game too easy, try Rect Pushers. Similar concept but more sophisticated game mechanics.
https://itunes.apple.com/us/app/folding-blocks/id1459650728?mt=8