A quick trawl through the catalog of Camera Replacement apps on the Apps store will soon reveal a plethora of apps laying claim to being the greatest thing since sliced bread. It can be a little confusing to sort out what you need and what really works.
My eBook “Ultimate iPhone DNG” has information regarding App choices but you might also like to check out this little video where I discuss the items/features that you would ideally be looking for…fact is some of the apps have deficits that rule them completely out of contention.
Buy Ultimate iPhone DNG on the iBooks store:
https://itunes.apple.com/us/book/ultimate-iphone-dng/id1274334884?ls=1&mt=11
Check out the video here:
iPhoneRAW 