Design an App Mockup

The app is already mocked up and working, but it just looks very basic and I want it to be looking extremely modern and professional when completed. The app is both IOS and android (two separately built platforms) I need somebody who is good at design and is willing to completely test out the app to make a list of everything that is not working and design changes with will make the apps overall look better. Your job will be to put together a detailed list which I will then send through to the developer. The app consists of 13-16 pages - both iPhone and android (different apps). This should take about two hours work.