Why isn't it possible to just use your iPhone or any other Bluetooth (4.0 low energy) device, they should have a unique mac address and could be used for something like this.
How/why is this better?
I just scan around and there is another app in the Mac AppStore: https://itunes.apple.com/us/app/keycard/id578513438?mt=12
And some tutorial: http://mac.tutsplus.com/tutorials/security/use-your-phone-to...
which reference another open source project -which seems left in the water for the past few years.
Anyway the concept overall is good but I think I am not the target market: not really interested to add one more BT devices that I need to carry.
Good luck to the team