I think the time for indie iOS developers as real contenders has passed. Yes, indie developers can still make great apps, but it's no longer realistic to compete with the production quality that is often seen in the top 10, or even top 50 on the app store. If you really want to work with a small team, you absolutely need a great designer who's as invested in the app as you are. I suspect that in the near future (if not already), even a great coder / designer team will have trouble competing with the distribution and marketing advantages of larger names.