It's really a judgement call, but trying to remove every API dependency before you launch is most likely over-optimization. I'd suggest focusing on launching and refactoring later on, for two reasons:

1. If the app doesn't generate revenue, the time spent refactoring now will be wasted.

2. Your users won't care about whether or not you're using APIs when it's time to sign up.

Just make sure you have a plan in mind for what to do if the APIs do become unavailable, make sure the dependent code fails gracefully, and until then, just keep on truckin'.