If you have ever done any development in Xcode then you know that seeing your work in a simulator window is less than inspiring, It also doesn’t help that the simulator doesn’t give you the context of the physical device your app will be running on so you can make design decisions about font sizing, button spacing and much more.
This is an even bigger problem when, like in the case of Apple Watch, the device isn’t available so you can’t even port your code onto ta device to get the answers you need. My rock star lead iOS developer recently came across Bezel which is a free developer tool you can add to the iOS Simulator. It shows a window that looks like an Apple Watch and projects the contents of the Simulator’s watch window into it so that you can see what your app will look like in the context of a device frame surrounding it with the amount of extra black margin that it will have, etc. You can also change the style of the watch and band so you can even see what your work with look like with a huge number of the possible watch combinations.
It sounds like a simple things but I’ve found it to be a huge help for my design and even the ability to quickly pull screenshots in the context of the watch to share which can be simple but a huge time suck. You can download Bezel and all the frame options here.