I really like this property mapper class from Krzysztof Zabłocki. No subclassing, no dependencies just a simple data structure to describe mappings between dictionaries and properties. The problem being solved by this is not enormous but for the amount of times this kind of code gets written this is a worthwhile little helper.
The idea of using the Dropbox Datastore API which automatically persists Core Data objects makes me very nervous but that is exactly what Jonathan Younger has created here with ParcelKit. It's an interesting idea but you will want to do a lot of testing with this, especially around the automatic conflict resolution in the Datastore API which might be OK for a simple KV store but once you start putting complex objects into it? It's going to be a rocky ride. This is no criticism of the framework here, just that laying Datastore under the familiar feel of Core Data might give a level of trust which is misleading.
Jonas Budelmann with a new DSL for Auto Layout which is much more readable than lines and lines of layout constraints being created manually.