We have just released for TestFlight support in MonoDevelop.

This makes it simpler for developers to deploy their Ad-Hoc builds directly to Testflight, we added a "Publish to TestFlight" option:

The first time you upload to TestFlight you must provide your authentication tokens:

And after that, the IDE takes care of the rest:

This is built on top of our enhanced IPA Packaging support in the same release.