We’ve all done it. You put your keys down, and five minutes later you have no idea where they are. You could swear you put your phone on the kitchen table last night, but it’s not there now. You put your bag under the restaurant table and then walk out without it. Doing all three in the same week might suggest the help you need is more medical than technological, but for those occasions when you do one or other of them, Proximo is designed to help.

Bluetooth tags also provides some degree of protection against theft, where you’ll be alerted to any of your tagged items walking off.

There are a number of different tagging systems on the market, with varying levels of functionality. Proximo is one of the more sophisticated, offering five different features …

Proximo Starter Kit

The starter kit contains one fob and one tag. I’ll discuss the difference between the two later in the review, but for now say that you’ll only need one fob while you may want additional tags.

Both units are made from the ubiquitous black ABS plastic. The fob is around two inches by one inch by half an inch. It has a concave button, and looks very much like a much smaller car key blipper.

The round tag is about 1.5 inches in diameter and again around half an inch thick. Both units have metal rings embedded in them to attach to a keyring, and the starter kit contains small and large keyring-style loops to attach them to bags or similar.

Both devices use the standard CR2032 watch batteries used in most such tags, which Kensington reckons lasts around six months. I hammered mine a bit in testing, so expect less, but will update when they run out. You need a Philips screwdriver to replace the battery, which is slightly fiddly but more secure, and as a nice touch Kensington includes a miniature screwdriver in the starter kit. Replacement batteries are cheap.

Locator

The most basic functionality is like those old whistle-activated keyfinders some of you may be old enough to remember: whistle at them, and they bleep so you can hear where they are. In the case of Bluetooth tags, whistling is replaced by pressing the ‘Find’ button on the free Proximo iPhone app. In this case, Kensington sent me two starter kits, so I have two fobs and two tabs – one less than the maximum of five devices supported by the app. Just hit the ‘Find’ icon for the device you want to locate.

One weakness you’ll see here is that the homescreen of the app doesn’t label the devices, so although you can tell the fobs from the tags, if you have multiple tags you won’t be able to tell which is which from this screen. To identify a device, you have to touch the image.

The fob is louder than the tag. When I first tried it, I didn’t think the tag alarm was loud enough, but I found that in practice I could hear it from anywhere in a three-bedroom house. With the fob, I could hear it from about fifty or sixty feet away.

Cancelling the alarm is slightly unintuitive: on the fob, you can silence it by pressing the button, while on the tags you have to silence them by touching the ‘Dashboard’ text which returns you to the app’s homescreen.

Proximity alarm

The second function, also common to most such devices, is intended to alert you when you leave something behind – leave the house without your wallet, or the restaurant without your bag, for example.

As soon as you go out of Bluetooth range, an alarm sounds on your phone, as well as the alarm sounding on the fob or tag itself. While the alarms on the device are limited to a single ‘siren’ type sound, you can set custom sounds on the iPhone for each device. There are 14 built-in sounds, or you can choose a track from your iPhone library.

You can also choose whether the iPhone alarm sounds once, or continuously until cancelled.

As is the nature of Bluetooth, the distance at which a device goes out of range is variable, but typically it will be 40-80 feet, depending on walls, doors and so on. Usefully, it tends to sound pretty quickly if you move outside a building.

So far, so standard: this is the functionality you can expect from any of these devices. Proximo, though, goes three steps further than most.

Quiet mode

The proximity alarm is designed to alert you when you’ve left something behind while out and about: you wouldn’t usually want it to sound at home.

I did find that the alarms could occasionally sound even when 15-20 feet away, so this is a very handy feature to avoid false alarms at home – you especially wouldn’t want an alarm to go off while sleeping.

With Quiet Mode, you can set your home address as a location, and it then won’t sound the alarms while your phone is at home. It will still alert you if you leave something behind when you go out, as the quiet zone is based on the location of your phone rather than the fob or tag.

Here you can see that the app recognizes I’m at home and so won’t sound any of the proximity alarms even though they are all live.

If you don’t want to be alerted to a specific tag – for example, one in a bag that you’re not taking with you – simply touch the alarm icon to cancel it.

Distance indicator

Another unusual feature is that the app shows a visual distance indicator for each device. Again, the randomness of Bluetooth propagation makes this a relatively crude tool, but it is surprisingly useful in closing in on the errant item.

What is shown here, for example, is fob 1 in the same room, fob 2 in an adjoining room, tag 1 downstairs in the kitchen directly beneath my office, and tag 4 as far away in the house as it’s possible to get.

In practice, I found the sound alone was enough anywhere at home, but the visual indicator did work pretty well in a coffee shop and bar, where it was impossible to hear the alarms on the devices.

I wouldn’t describe this feature as a must-have, but it’s a nice extra.

Phone-left-behind alarm

Finally, I mentioned earlier that you may want multiple tags, but will only need one fob. The reason for this is that while tags only have the standard one-way communication – triggering them from the phone – the fob has two-way communication. If you forget your phone, the fob alarm will sound to alert you, and will also trigger the alarm on your phone.

You can see this function demonstrated in the promo video at the top of the review.

Conclusions

I’m a big fan of simple technology that reliably does a useful job, and Bluetooth tags are a good example. Stick one on a keyring, in a bag or whatever, and then forget about it. Lose track of the item, or walk off without it, and you get alerted.

There are a whole bunch of these things around now, and Proxima offers the most functionality that I’ve seen to date. At the official retail price of $60, it would be a tough call – the added features over most competitor products are good, but that’s a lot of money to tag a couple of items.

Note that the Bluetooth LE used by Proxima and similar products is only supported on the iPhone 4S, 5, 5S and 5C.