Ever since getting my Sony SmartWatch in December 2012, I've been impressed with it's architecture and simplicity. I actually wished I was part of the team that built that watch, because it looked like a lot of fun!
A few months ago, I came across the "Make your own smart watch" instructable for the RetroWatch. I posted it on the House4hack mailing list and there was immediate interest. Peter van der Walt designed our own PCB (to make the watch smaller, and add more buttons), did a group buy, and now many of us have working watches, albeit with very limited functionality and buggy firmware.
I wanted to make the watch capable of opening the House4Hack gate and door (as I'd done with the Sony SmartWatch), and have custom clock faces, so I decided to write my own firmware and app. I started on this and in less than 2 days, I have a working watch with my own firmware! As you can tell from the attached images, I had a lot of fun doing this, and it is immensely satisfying to have it working well enough for actual use!
This is still very much a work-in-progress. The code and schematics are at: https://github.com/tobykurien/OPHW-EL-BlueWatch
This app is under development, check back soon for more information.