Q:

minimum iOS version for external testers using iTunes Connect / TestFlight Beta Testing

What is the minimum iOS version for external beta testers using iTunes Connect and Apple's new TestFlight Beta testing? (not the old pre-iTunes-Connect TestFlight)
Our app has many users on 4th-generation iPod touch devices which are limited to iOS6, so before we release the new version of our app we want to make sure we get beta test coverage on those old devices. 

A:

According to Apple's page:

TestFlight Beta Testing requires iOS 8 or later, and can be used in all 155 countries where the App Store is available.

