Install old version via TestFlight

I found a workaround to test older builds with TestFlight. You can just use the link provided in the email you received when you uploaded the older build for testing. You will see something like this.

To test this app, open TestFlight on your iOS device using iOS 8.0 or later and install the update.

Tap on "TestFlight" in the above line. This will open TestFlight with a link to the older build. And you can install it if it hasn't yet expired.

Hope this helps!

Update

As of April 11, 2017, TestFlight now supports multiple builds. https://developer.apple.com/testflight/release-notes/

You can navigate to the Previous Builds section of the app in TestFlight and get access to builds which are up to 90 days old.

Latest working way to find previous builds:

• tap on the app icon ( current one )
• scroll to the bottom , you will see 'Previous builds'
• Tap on it and you will see all previous builds.

Thanks