Repeat from 2016 but updated for 2017: You get what you pay for :-) But I think all you need is something like Lightroom Mobile but programmed from an iPad Pro point of view first (i.e. including stylus and keyboard and solving the external storage / SD import problem AND not needing desktop sync or any other legacy kludges)!!!!!!
21st century cameras are social and on the internet and awesome-ized by software and sensors