I want to release an update to my ad hoc build that exists on my various devices?
UPDATE: I don't mind doing it manually for each device my question is, how do I update the app's without deleting them first off the device. i.e. I want to keep the database on the device in tact...itunes doesn't allow this.
I guess you will have to install a new build on every device via iTunes.
Or you can try TestFlight, it's a great tool. And you can just install a new builds from the device itself. And if you include TestFlight SDK you will be able to get all the sessions and all the crashes of that app(with stacktrace).
Update: use TestFlight. You don't have to delete the app in order to install a newer one. I use Core Data and NSUserDefaults and after installing a newer build nothing is being lost. So I guess it's something you are looking for.