Why can't I use my Fitbit for Smart Lock? I just updated my Nexus 5 to Lollipop, and the feature I'm most anticipating is Smart Lock — the ability to keep my phone unlocked when it's near me but still have strong protection if lost or stolen.

I figured that since I have a Fitbit One in my pocket pretty much whenever I have my pants on, I'd use that as the "key". It syncs by Bluetooth, so I figured I'd be all set.

However, when I go into Smart Lock in the settings and attempt to add a Trusted Device, it doesn't show up in the list. Why not?
Bluetooth Low Energy devices can be used for Smart Lock, but they need to be paired at OS level and it seems that the Fitbit uses some kind of pseudo-pairing at app level. From the Fitbit manual:


  Unlike standard Bluetooth devices, like headsets, your Fitbit tracker will be set up directly through the Fitbit app and not through your Android device's Bluetooth pairing settings.