Fix and Update mobile application

I have a mobile app that a freelancer helped me build. Here is the link to the app in the app store [login to view URL] There are multiple issues with it but the biggest problem is it fits the iphone 5 screen but the bottom cuts off in older phones (like iphone 4s and 4) It also doesn't work well in background mode. Please download, test the app and remove all bugs. The app is free in the app store. I will send the winning freelancer the project files.