Nulla is a solitaire puzzle app game.  The object is to combine adjacent numbered tiles that are the same and whittle down to just 1 tile.

Look at the 2nd image.  Combine the two 11's and they turn into a single 10. In this case move the left 11 over to the right 11 so that the resulting 10 is adjacent to the one that's already on the board.

The puzzles are not hard. However, there's a scoring system. Every correct move counts as 1 point. If you make a mistake, you back to zero.
My high score is about 200.

The graphics and overall presentation are very good.  I recommend this for novice puzzlers and for those who like peg solitaire games. Though it's not quite the same thing.
https://itunes.apple.com/us/app/nulla/id1144199581"mt=8

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