I perform UX reviews on the mobile and web apps on the basis of Nielsen's 10 heuristics. My report not only point out the problem but also point out the heuristic which has not been followed. I also priorities the issues for the developer or the UI designer which should be fixed on urgent basis. In the last of my report I include 2-3 slides of my recommendations / suggestions on the basis of whole user flow, navigations, options that should be used on left / right gesture etc...
What the Seller needs to start the work
- If their app is live, access to it
- If it's not live then demo link
- if it's not any of those then clickable prototype on invisionapp / on any other app like this