I think this works well for what I would use it for. I saw the poor reviews stating you cannot hear it over city traffic.
I bought this for two reasons. One is to track a wallet that is usually lost at home. The sound volume is more than enough to hear it. I also bought this for my computer bag. I know this sounds stupid but I drive to work every week day and put my computer bag in the back of the car. About once a month, I will get paranoid and get scared when I am on the highway that my bag is not in the car. I cannot see the back because of the headrests. So maybe about once a month I will get off an exit and stop to open the back to look. Even with this, about once a year, I will get to work and find out I forgot to bring my bag so I waste 60 minutes driving back to get my computer. This will help a lot. I also like the idea that I can replace the battery by myself.

Update: about 7 weeks after using the rechargeable lithium ion batteries, one just got the low battery warning so I recharged it in about 2 hours. Also the panel on that TrackR Pixel which should not come off came loose on one end. I just glued it back on with cyanoacrylate glue so it is working fine again.

I got a 4-pack for the holidays and they have been great so far. We've attached them to two sets of keys shared by the family, a purse, and a car. They definitely work as advertised; it is so easy to page the TrackR and to have the TrackR send an alert to a lost phone. The last known location is very helpful to. My only reservation is that I haven't yet had the opportunity to see how well the Crowd Locate feature works in the event that we lose a device way off the beaten path... Price is right, the app is easy to use, and the devices are stylish.

I'm a longtime TrackR customer and rely on them to keep track of my stuff. They've kept me from leaving my phone or keys many times. One time I was traveling, waiting for a colleague in a hotel lobby. He ran a little late, I got distracted, and when he showed, I jumped out of my chair so we could head to our meeting. We were a few steps outside the hotel door when my TrackR Bravo started ringing. I ran back into the hotel to find my phone sitting on the lobby chair where I had left it. I now have TrackR's on my car key and backpack, and in my wallet. I have a Keyport key organizer with TrackR built in. I prefer not to use the audible alarm. Most of the time, when I forget something, it's at the office. So if I'm home and can't find my house keys, I bring up the TrackR app on my phone, see that it reported my keys were at the office, and relax that I know where they are.

Seems to work just fine. It doesn't have a far range, because, well it's bluetooth, but, if you are in the vicinity, you can hear link up and find it. I put it on 2 iPhones & 1 Android. If putting on more than 1 phone, shut off bluetooth on the other phones, cause only one device can link up to bluetooth devices at a time. All 3 phones can send signal to TrackR, and the TrackR can make the phone beep. If you are losing your keys in your place this will def save much time. I shut off bluetooth and location services till I need it, but when I need the keys, I turn on bluetooth & GPS, and I can find em. Plus you can change the battery unlike the Tiles. Most time consuming part was updating the iPhones to get the latest iOS to download the Trackr app. Works good. The time I saved is well worth cost of 4 devices.

Works exactly as expected. The reviewers that think that this device is some sort of magical coin that instantly connects to your phone are living in their magical dream land.

This is a blue tooth device. Just as your Bluetooth mouse gets jumpy when a table or something gets in between it and the dongle, this device may take some time to connect if it's not within direct line of sight with your phone (which it probably is not if you can't find it).

This device will help you know when you last had your wallet and phone on you at the same time, and the general GPS location at that time. Flipping couch cushions is not too tough a job after that. More importantly it tells you whether you left it at work or the restaurant.

UPDATE:
After replacing the battery with another set I bought on Amazon, the new batteries were too thin, so it didn't work unless I squeezed the bravo. I fixed this by squeezing a folded piece of aluminum foil on top of the battery. Cheap hack but it seems to work.