1. Create an account on TestFlight (http://testflightapp.com) and with “Developer” option checked.
2. Log in to the TestFlight web site and “Add a team” for your app.
3. Add teammates, either testers or developers. (PS. Recruiting testers from public is also available)
4. Ask your teammates to register their iOS devices following the instructions in the Email. (Do it on their iOS devices)
5. Once they accepted to being the teammates and registered their devices, you will be able to see their devices information such as device model, iOS version, and UDID.
6. Add their devices/UDIDs to your Provisioning Portal -> Devices.
7. Modify the Ad-Hoc provisioning profile to include the newly added devices and install the updated provisioning profile to your XCode.
8. Build your app in Ad-Hoc mode and locate the YourAppName.ipa.
. For XCode 4: http://support.testflightapp.com/kb/tutorials/how-to-create-an-ipa-xcode-4
. For XCode 3: http://support.testflightapp.com/kb/tutorials/how-to-create-an-ipa-xcode-3
9. Log in to TestFlight web site, click “Upload Build” and follow the instructions to finish uploading the app.
10. Your teammates will be able to install the app you just uploaded to their devices with TestFlight app on their iOS devices.
Of course some small changes might be there over the last year with new releases, but the process remains roughly the same.