Gravitations: free physics puzzle app for ipad, iphone

 Gravitations is a free puzzle app game. The  object is to figure out a flight path that will go from 1 satellite to another, pick up a marooned astronaut and deal with fuel, gravity, black holes, worm holes etc.

 

I did all the Flight School levels. You can set up your own puzzles and post them for others to solve. Or, you can solve the puzzles that others have created.

Did I mention that Gravitations is free? Very cool puzzle app.
http://gravitationsapp.com/