I found this a few days ago, sort of as a hidden treasure, and just in case others don't know, there is a way in iMaginator to do precise numeric editing. It's not obvious, and I didn't read it in the guide. Add almost any effect to an image. The ones with the small blue dots along a the slider (for want of a better description) in the controls are the ones I'm discussing here. Double click on the blue dot, and you'll get numeric controls for that filter/effect, down to two places after the decimal. Some of the effects, such as Source Atop already have an options button which I'm sure most people find soon enough. But the numeric controls were pure pleasure to find
While the numbers give exact values for the slider, it is a great bonus to have as a numeric editing tool for those of us that like that kind of thing.