Pull-to-refresh makes sense when adding new cells to the top of a UITableView (as in a timeline), but it doesn't make sense as a general refresh gesture as they show in their example. Hopefully it won't start being abused too much.
Wow.. my first rails project was going to be exactly this. Almost the exact same features and UI. Kind of unsettling =)
Since you destroyed me to the punch, my only suggestion is to have some sort of tagging system, so that users can search by control type (i.e. button, facebook, alert)
