UPDATE

On the next update make a TOOL/CONTROL box in the bottom left corner, replacing the random feed. In this box, you can customize anything you want to do (with buttons and sliders) to make a colorful and elaborate simulation, which is a lot easier than memorizing the controls on the keyboard.
I gave you 5 stars, so just make it easier to control the things.

BUT WAIT
there should be a mode similar to Spawn Glow, which is free for iPhone.

TheAndrewBen about Gravit