They're not just for keyrings, you can attach a Tile tracker to anything precious. Keep track This is exactly the situation where a Tile tracker would have saved the day. Roughly the size of a casino chip, it's designed to attach to your keyring or other precious items so you can locate them with your Apple/Android smartphone. The tracker doesn't contain a GPS chip or mobile broadband access, instead it relies on Bluetooth to link to your phone. The Tile app will show the last known location of the tracker on a map. Of course this doesn't help if you're at home with your keys, as the tracking is not precise enough to tell you whether they're underneath the bed, behind the couch or hidden in a toy car. That's when you can push the button in the app to make the tracker play a tune. Alternatively you can press the button on the tracker to make the app beep, should you misplace your phone. You can also locate your phone on a map via the Tile website.

Along with finding items misplaced around the house, the Tile ecosystem can also come to your rescue when items are lost or stolen in public. You can put out an All Points Bulletin on the Tile network, at which point every Tile app will be on the lookout for your tracker – reporting back to you when it's located while preserving your privacy. Turn Pro Tile trackers have been around for a few years and there are several models to choose from. The original Tiles costs $40 each or $120 for a four-pack, while the new Pro models – Sport and Style – bump this up to $50 each or $90 for a two-pack. In return the new Pro models double the Bluetooth range, reaching up to 60 metres depending on what lies between your phone and the tracker. The Pro models also double the volume of the alarm so you can hear it from further away, plus they're waterproof with an IP68 rating – surviving complete submersion for at least 30 minutes. Bluetooth typically cuts out when an object is submerged, but you can still ping the Tile Pro when you've dropped it in a glass of water – although the sound is muffled.

Put to the test in a narrow three-story house, the Bluetooth range is great enough that when an iPhone 6 is on the top floor in the front room it can detect the tracker on the bottom floor in the back room. That's only a distance of about 15 metres, according to my friend Pythagoras, but with a lot of stuff in between. I don't have a standard Tile at hand for comparison, but your typical Bluetooth speaker drops out in the same location. Of course if your keys are 60 metres away then they're probably outside, and here the Tile Pro struggles. With the tracker on the dining room at ground level, my iPhone struggled to detect it from next door's driveway. It has more luck if you've left the Tile app running in the background, rather than launching it when you need it. With the phone and the tracker both out in the street, my phone can link to the tracker from about two houses away. Beyond that, if the phone detects a faint signal you're told the tracker is nearby so you know you're on the right track. Tile offers a choice of cutesy tunes for the tracker to play when you ping it from your phone, but it really needs to be louder – there's a choice of two volumes but even the loudest might not cut it if your keys are lost at the bottom of a bag a few rooms away.

It's a shame you can't opt for a blaring klaxon to give you the best chance of hearing it in the distance. Lose something precious in a crowd and you might struggle to hear the tracker, although there's also the option to play Hotter Colder with the app's proximity sensor. Stay in charge Tile doesn't charge a subscription fee but unfortunately you can't recharge the trackers. They're guaranteed to work for 12 months, after which Tile offers a discount on replacements, so you really need to view it as an ongoing expense rather than a one-off cost. Of course leaving Bluetooth switched on constantly also takes its toll on your phone's battery, although iOS recognises the Tile Pro as a low-power HealthKit-compatible Bluetooth device which helps with power management. It's also possible to link a Tile to more than one account, so you can use your partner's phone to find your keys in an emergency. So what's the verdict?

A Tile Pro can come to your rescue, if especially if you misplace items regularly, but don't expect miracles in terms of range and volume. It'll cut it around the house or office, but in public you might still rely on the kindness of strangers to be reunited with your lost items – which is when the Tile network can save the day.