There is only one file type that uses the .MOBILEPROVISION extension:
Xcode Mobile Provisioning Profile
File used by Apple Xcode, a software development IDE often used for creating iPhone apps; contains a provisioning profile, which allows an app to be uploaded to a limited number of iPhones or iPads while it is still in development.
Provisioning profiles can be created through the iOS Provisioning Portal, which is located within the Developer Program Resources section of Apple's Member Center Web portal. Provisioning profiles can only be created by registered developers and they must be assigned to an iPhone or iPad using the device's unique serial number.
Once a provisioning profile has been imported through Xcode, the application associated with the profile can be uploaded to the test device and run.
Updated: September 11, 2015