This app was mentioned in 2 comments, with an average of 1.50 upvotes
How's this one? https://play.google.com/store/apps/details?id=by.orangesoft.photoprogress
iphone only :(
I find this one nice: https://play.google.com/store/apps/details?id=by.orangesoft.photoprogress&hl=en
Easy to compare 2 pics side by side and track changes