So we've already taken a look at some of the issues we've faced building our Whiskr Apple Watch app, next we're going to look into how we shared data between the iPhone and Apple Watch app. This was probably one of the hardest aspects to learn and get right, and the current documentation isn't all that great!
To do this we'll have to create an App Group which is essentially a space which both apps can use. It was brought in with the exetension framework in iOS8 so apps can communicate with their Today widgets, or custom keyboards, and amongst other applications.
The first thing we have to do is add the app group capability to both our iPhone and Watch Watch Extension targets.