SpreadSet from Chen Xue was a surprise for me.  Look at the 2nd image. The object is to Spread a ribbon from the 16 square to cover all the squares.  Yawn.
Then I realized that level 7 or 8 was impossible. Until I realized that one ribbon can push another ribbon out of the way, if there's room.
There are only 25 levels, which I love!  I was stuck on level 18 for a couple of days. Must have attempted it 30 times.  At the moment I'm stuck on 23.

The graphics aren't great, but that's fine.
https://itunes.apple.com/us/app/spreadset/id1139441015"mt=8

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