Cyclotron is a fun and satisfying particle app. Touch the screen and the particles go wild.
Using multiple fingers changes the way the particles behave.
Great to mess with when you're bored and have some time to kill, need visual stimulation or want to keep the kids busy.
Removed the menu button. To show menu now, you must tap a corner of the screen.
Atomic Toy 
Tesla Toy 
Laser Lights 