We had the old (ex-Limbo) version still sitting in TestFlight, but found that some users hadn't realised that they were on that version rather than the current, maintained version so access to that version now been switched off.

If you find you've just lost access to Liftoff!, please join the new TestFlight version at https://testflight.apple.com/join/jKENkGjX -- you should see version 0.10.7 there, with many, many new and improved features!