I needed to do some push notifications to Android and iOS, so I put together a library for doing so. It's early, but is functional thus far. No API guarantees, of course. C2DM still uses the (newly) deprecated Google ClientLogin authorization. I still need to do some research for moving that to the forward supported OAuth2 authorization. The APS client uses your TLS certificates registered with the app store. It speaks the "enhanced" protocol, which lets you know about errors. Occasionally. Sometimes. If you're lucky.
-- Christian Hergert 2012-05-17