Good RAW photo app

Have you tried Adobe Lightroom? I always edit my DSLR RAW files on a PC but I know the editor works great on mobile as well and it works with the RAW files created on Samsung phones.
 
I second @L0n3N1nja's recommendation. Lightroom CC works really well. It also synchs with Lightroom for Windows or Mac, but you have to have an Adobe CC subscription, which isn't free.