Ask HN: What are useful things to know/do when launching your first mobile app?

I've read some Steve Blank and Eric Ries material and have understood that it's very important to use the first version of the mobile app to test user behavior.

I'm building a ride sharing app, that finds you a ride with acquaintances or someone you have at least a mutual friend with.

That said, I would love to know more about mistakes and successes you had when you launched your first app