I work on an app that involves working with many photos and PDFs and users would like to be able to markup those files. Those files need to get back into our app, the more streamlined that process, the better. Obviously Skitch is great for doing that markup and, though I haven't purchased the PDF add-on yet, I see I can share PDFs to Skitch from within my app. Would it be possible to save any changes to the PDF back to my app in a more direct manner? I assume it would take some custom programming around inter-app sharing on my side. Also, would the same be possible for images (jpg, png, etc)? Skitch doesn't even appear as an option when sharing an image. If I can't do both PDF and images, I'll have to implement a basic markup tool myself.