It is cool gaget. Have a look at review:
Bluetooth tracking gadgets can be a big timesaver. With the TrackR Bravo, you attach a key-ring sized fob to something valuable to you: your keys, your bike or your wallet. When you can't find the item, you check the app to see where it was last seen and when you're in that location, you can activate a siren to make it easier to find. See also: Tile (2nd-gen) review
I originally reviewed the Bravo at the start of 2016. Since then I have tested almost 10 more, and have updated this review with my long-term experience. To save you reading the whole thing, here's the short version: I found the Bravos to be unreliable.
Some stopped working entirely (one when it got wet) and the batteries in most others had run out in a matter of weeks. Another one decided to unpair itself from my phone.
I tried replacing batteries which had gone flat within a couple of months, and they too ran out way, way before they should have done. What this all means is that you cannot rely on the Bravo to keep track of the things which are important to you.
You can buy a Bravo for £24.99 ($29.99)..