Theming apps (the ability to change up the color scheme for an app from say, a white background with blue links to a light green background with green links) is a pretty common feature across a lot of apps. It’s one of the core features of the new “Twitter Blue” subscription, Tweetbot and Twitterific have had it for awhile, my app Apollo has it (and a significant subset of users use it), and it’s basic table stakes in text editors. When you use the heck out of an app, it’s pretty ni...
