I maintain Frank, a tool which lets you write automated acceptance tests for your iOS app using Cucumber. I've been trying to reduce the hurdles in getting started with Frank. My latest attempt is to record a tutorial screencast showing how to take your existing app and 'Frankify' it.
'Frankifying' an app is the process of adding a separate Frank target to your app which has the Frank server embedded into it, allowing it to respond to automation commands. It can seem like a bit of an intimidating process at first glance, but it's actually very simple. Hopefully running through the whole process in a 7 minute screencast demonstrates that.
Derek Longmuir has also contributed a nice in-depth tutorial writeup (which I was following along with when I recorded the screencast).