When you need something entertaining and fun to do, look no further than to this app. I bought for $.99, and it is one of my most played apps. All around fun, and definitely worth the money. If I could make any changes, I would add arrow controls to the field pop-up controls for fine editing of the strength of the attract or repel, when playing with ions on low speeds I sometimes take 5-10 uneccesary minutes fine tuning the strength of the field. also, allowing for a raise of the ion cap would be fantastic. Test out the true capabilities, because even at 20k ion bits, the graphical abilities of the iPad don't show any strain.
Otherwise, Keep It Up!!!