Joints Puzzle Game comes from EggShellGames.  It's a lot like Lights Out.  The object is to get all the nodes green.  Tap on any node and it will change. It's neighbors will also change color.   The graphics are very good.
These are hard!  Of the 144 levels, I've done about 25.
https://itunes.apple.com/us/app/joints-puzzle-game/id1296723568"mt=8

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