Tutorial about UIGestureRecognize. Also contains an example of using Fastlane to build and run tests, create coverage reports in a cobertura style and upload those to Codacy.
Provides storage and incrementing for correct and incorrect answers. Every time you answer a question correctly the next time you will see it will be farther in the future.
Harking back to the old days when SDK's would provide you with a preview app of what the SDK can do. This is an implementation is Swift for UI animations.