I could easily have written twice as much about Core Graphics, because it's capable of some extraordinary effects. Clipping paths, gradients, blend modes and more are just a few lines of code away, so there really is no excuse not to give them a try! And if you don't give it a try yourself, don't worry: we'll be drawing with Core Graphics in project 29, so you can't avoid it.
This project has given you a sandbox where you can play around with various Core Graphics techniques easily, so I would highly encourage you to spend another hour or two tinkering with the code in your project. Use code completion to try new functions, change my values to others to see what happens, and so on. Playing with code like this can help you to discover new functionality, and will also help you remember more later. Have fun!
One of the most effective motivators of success is sharing your progress with other people – when you tell folks what you're doing and what you've learned, it encourages you to come back for more, which in turn will help you reach your app development goals faster.
So, now that you've done all the hard work it's time to share your success: tell folks that you've completed this project, either by clicking the button below to start composing a tweet, or by writing your own message from scratch. This will definitely encourage you to keep learning, but it will also help other folks discover my work – thank you!
Paul Hudson is the creator of Hacking with Swift, the most comprehensive series of Swift books in the world. He's also the editor of Swift Developer News, the maintainer of the Swift Knowledge Base, and Mario Kart world champion. OK, so that last part isn't true. If you're curious you can learn more here.