Developing for Apple Watch

Creating Your Apple Watch App

While going for a run, you want to know things like how far you’ve traveled and how fast you’re moving. Plenty of apps exist to do this outside, where your iPhone gets great GPS reception, but we want one that works great indoors on a track. That is the purpose of the Apple Watch app we’ll be creating in this book. We can’t access the step counter of the watch from our WatchKit extension, so we’ll be building a rudimentary stopwatch; every time users cross the starting line of the lap, they’ll tap a button to mark a lap as completed, and the app will mark the time they tapped the button. To go along with this user interface, the app is named TapALap, since you’re tapping a lap. I know—amazing name. Every track is ...