Another one is HockeyApp. The thing I don't like about TestFlight is that your testers also require an account. I believe HockeyApp does not. The last thing people want is yet another online account.
Ibetatest wasn't good. People just downloaded my app and never tested it. Wasted 2 weeks. Reviewfordev cost more but I got what I paid for, it felt for controlled rather than hoping a tester joins your project and hoping again they do something.