I'm afraid it was one of those things that got forgotten about... I am however looking into doing a slightly different version with an environmental sensor. I figure that, although making your own is always better in my opinion, a bluetooth-to-phone watch will never have the same functionality as my pebble, or any other watch which was what I was going for, but I think a dedicated environment watch, perhaps even with a heart-rate monitor or something, could work really well. I do the DofE Award, and as part of it you have to go on an expedition without your mobile phone. It'd be really cool to kmnow the temperature, and other stats, without a phone so I think this could be quite a fun thing to make. Actually, re-reading this has kind of inspired me to get re-started with this!
I have used GEMMA before, but not for anything like this, and having used it for something much simpler, I wouldn't really recommend it for a large project like this!