You should be well aware by now that the Core Data stack that gets added when you check "Use Core Data" in Xcode is more about getting you started than being a production ready/best practice implementation. So when thinking about real apps, who better than Marcus Zarra to school us on what a modern implementation looks like.
There are lots of beautiful charting libraries that do one very specific thing and there are a few not quite so beautiful charting libraries that try to do everything. This is a port of MPAndroidChart by Daniel Gindi and it looks to strike a nice balance between the two.
This is something a bit different. By doing a long tap on the back button in a navigation controller it opens up a iOS multitasking style view with the stack of controllers that you can scroll through and select to move to that point. I can see this working really well in an app where you end up deep in a navigation controller (I'm looking at you TweetBot, but in a good way 😄).