Hi @mac1! Thanks! So far, people have really enjoyed our features 
Correct, after you download Testflight on your iPhone, you’ll need to click the link again. That will open TestFlight and allow you to download the app. If for some reason that isn’t working, send me a PM with your email address and I’ll get you added.
As far as guidelines to implementing the features, check out our documentation. We cover how to use each feature, and best practices for implementing them in your Bubble app.
As far as Qoins, we actually are still using Bubble, just only for our backend/API.