I used this to narrow the search considerably for a lost FitBit One. It was syncing so I knew it was in the house. May not have all the “features” of the exclusive FitBit finder apps, but this worked for me. If there are several bluetooth devices nearby, select the one you want in order to listen to that signal alone. My FitBit was already labeled “One” in the list of devices. Try “Lightblue low energy bluetooth” app to figure out what each bluetooth device is if you don’t know.
Nathan__Y__ about Bluetooth Smart Scanner