There are plenty of situations where a single screen of an app might have several states. For example an empty state, a loading state and then the "normal" state where data is displayed. StateViewController from David Ask helps to manage this common scenario.
Everything you wanted, or needed to know about NSPredicate, all in one simple web page from Axel Kee. If bookmarks were still something that people used, I'd suggest bookmarking this for the next time you need to use NSPredicate. 😂
Quentin Jin with a smart looking Timer library, not just for delaying events relative to the current time, but also to schedule events for specific times. I particularly liked the ability to tie a timer to the lifetime of another object. Really nice.
Ryo Aoyama with a library designed to work with
performBatchUpdates on table and collection views to allow fast differencing and updating between two data sets. I'd suggest checking out the playground to get a sense of how easy this is to use.