Justin Williams recommends that you don’t spend more than ninety days on a 1.0. I’m with Brent that I want to see apps that take more than three months to make, but I still think Justin has the right advice.
Some apps are deep, and there’s no way around the time they’ll take to get right. Coda comes to mind. Overcast might too. A majority though – especially on iOS – are really all about one thing that makes it unique and everything else falls out of that one thing.
Don’t ship garbage. Do figure out what your app is really about, do the hell out of it, and then start shipping updates.