Does anyone know of an existing open source UI framework that would help with repetitive tasks like adding or editing core data objects with a UITableViewController with a fairly standard (but hopefully customizable) look and feel? When you are dealing with a lot of objects, it gets repetitive and redundant quickly.
If not, I'm considering starting my own project, but I don't want to reinvent the wheel.
Not really.
The closest you can get is the Apple provided NSFetchedResultsController. The sample code is basically the same for every app, with a few tweaks here and there (Of course this is no UI help).
Jeff LaMarche has a good implementation of the delegate methods that are a little better than what you find in the official docs.
http://iphonedevelopment.blogspot.com/2009/07/core-data-navigation-based-application.html