I love Parse, but their iOS devs ... I don't know what the hell they were smoking when they designed their iOS SDK. It's so poorly designed, that they've now introduced this horrible kludge to do something that it should have done out of the gate. A protocol for subclassing? Are you kidding?
ModelKit (http://github.com/jawngee/ModelKit) is an alternative Parse SDK I wrote out of frustration with Parse's offering, with the added bonus of having a swappable backend or no backend at all. I've used it on four shipping projects already. It has the additional benefit of working disconnected as well.