In Windows Phone 8, things got better of the front of reading the file system. It’s actually gotten closer to the Windows 8 with the inclusion of WinRT, and it now possible to read the content of files that were pretty hard (or impossible) to access directly before.
Reading the app package content files
There are some times when you need to access the content of the xap directly, and in Windows Phone 7, you were pretty limited to the use of the IsolatedStorage, but really did not have access to the content of the Xap, except for some location such as images or XmlDocument and the SQL CE engine using the appdata:/ scheme.
Things have changed in Windows Phone 8, and here’s how to read the WMAppManifest.xml file by yourself :