The book "Beginning iOS 7 Development" (ebook, print) contains a chapter which describes the creation of this app, step by step. The public version of TextShooter on github contains additional enhancements that were not covered in the book, including a Game Center leaderboard, a tutorial mode, and more.
Clone the repository, and use Cocoapods to install required dependencies. Then open
TextShooter.xcworkspace to dig into the project itself.
I mean it! Have fun with this! This game is really pretty simple, which means there's lots of room for improvement and expansion. One early reviewer made the very cool step of using Emoji characters instead of plain Courier font characters, for example, which made everything that much cooler.
Changes & Forking
If you have interest changes, pull requests are welcome. If you instead want to fork this and go nuts, be my guest! But obviously, if you're going to make an App Store release out of this, please use a significanly different name.