Have an old app that needs updating? From what I've found, even one year of no updates is enough to make you pull your hair out when you open up that old project in Xcode. This is the third post Steven has had on bringing an app that Apple pulled from the store because of age back from the dead. In this post, he talks about bringing the old code up to Xcode 8 standards.
This Old App: 2013 code, Meet Xcode 8 by Steven Lipton