I recently published version 2.0 of my iPad App Lightbox Trace, introducing a filter panel as an optional In-App feature. This really comes in handy, when your sketches don’t have enough contrast or you want to desaturate a colored image before tracing. Check it out!
Unfortunately, I ran into a problem with enabling the In-App purchase, so it just didn’t work for about a week. If you tried and got an error message about not being able to connect to the App Store, please try again. It really should be working now. If there are still any problems, please send me an e-mail. I appreciate your support!