It doesnt do as much as some photo editing apps but what it does, it does well. Manual edits (fade, vignette, & curves - all of which have a different (& easy to use) UI from most apps - require an IAP, but at only $.99 (in the U.S.) its hardly even pocket change.
I hear about the app from Erin Brooks (erinbrooks dot me) and it was an instant search and get (then buy) for me.
strangebirds about BLACK - B&W Film Emulator