Space Physics from Camel Games (a publisher apparently without a website?) is a Crayon Physics knockoff for your Android device. Crayon Physics was an innovative game released several years ago that took advantage of touch screen devices such as tablet PCs by allowing you to draw on screen objects and have them "come to life". I think that was a bit blown out of proportion as demos showed cars driving and such whereas reality has the game recognizing simple shapes such as lines and circles and moving them based on their contact with other shapes.
The game does offer a Lite trial version which is always appreciated and for $3 its definitely worth it. I think a level creator would be a nice touch... aside from that, more levels please.