The Apple Watch shipped with a captivating activity tracker. The center piece is a really cool spiral animation scheme showing the amount of activity during the day. This image is also shown on the matching iPhone Activity App. I have always wanted to see what it would take to implement this myself. The examples that I see typically use a custom drawRect override, but I always wanted to see what it would take to do with CAShapeLayers.

Implementing a 0-100% control is straight forward when using CAShapeLayer. But how do you implement a progress indicator that support progress values greater then 100%? This How To discusses a solution that I came up with along with it’s potential limitations.

Being able to display content on a external screen or device is a great capability to add to a iOS application. Especially how easy it is. This article will show the step required to to do this.