Best AI app builder for actually getting something onto the App Store?

Every one of these gets me a nice demo and then falls over at the parts that matter: auth, a real backend, a build that passes review.

If you've launched an iOS app that started in an AI builder, what did you use? And what did you end up wiring in yourself (backend, RevenueCat, push) to make it real?

Trying not to rebuild the whole thing from scratch three months in.