How do you save to Camera Roll – My Sketch - Pencil Sketches Review

I agree with the other reviewer. This is a great app and I particularly like that is one of the few drawing apps that allow you to process a photo in a format other than a square — but I cannot figure out how to save to my Camera Roll. I’m always having to email the images to myself so that I can then save them to the Camera Roll. I gather that there is a way to do it directly but I haven’t been able to figure it out. Please make it more clear within the app and, in the meantime would you post instructions as part of your listing on iTunes. Your users are tearing their hair out over this issue!
Review by KrozNest on My Sketch - Pencil Sketches.