Pixel Perfect feedback

I got Pixel Perfect for free. So I'm gonna take my time to give you guys some feedback.
Here are my thoughts:

* I'm missing a Contrast effect.
* The Saturation effect isn't anything like the saturation settings in Photoshop or Gimp. It makes my motives look high on drugs. Not very useful.
* The Hue is also weird. It's set to "colorize mode" and should probably be renamed to "Colorize hue" or something like that.
* The one-tap-preview is not necessary since I get the same preview when I double tap. Should be removed and double tap-feature should take its place.
* The thumb icons are a bit confusing. Would be better with a Save-icon (like a floppy) and a Cancel-icon (a cross).
* I don't like that the panel "flows". I think it should lock into the middle when speed is running out after scrolling.

Thanks.