FindMyBlue!

Why? Because its easy to lose your fitness tracker or other small Bluetooth device FindMyBlue designed to help locate missing Bluetooth LE (low energy) devices, such as the Fitbit, Jawbone, PhoneHalo and others. Known Compatible Devices: Fitbits (Force, One, Flex, Zip, Charge, Alta, Blaze, Surge), Bose QuietComfort Headphones, Snapchat Spectacles, Pebble Time LE, Samsung Gear S2, Forerunner 235 and Jawbone UP24It also detects MANY other devices, but, no guarantees.