How to restores files lost from application during upgrade of app
Your data should be recoverable!  


Download and install iExplorer on your PC or Mac.
Connect your iPhone to your computer.
Open iExplorer.
Your iPhone should appear on the sidebar on the left; double-click on "Apps".
Find Documents Mobile in the list that opens.  Double-click on it.
You should see a folder inside Documents Mobile called "Documents".  Drag and drop it to your Desktop and iExplorer should copy the documents in Mobile Documents to your computer.