Model: Proximo Starter Kit
Compatible: iPhone 4S/5
Kensington Proximo Fob & Tag Starter Kit
As the latest accessory to leverage low-power Bluetooth 4/Smart wireless technology, Kensington's Proximo Starter Kit ($60, aka Fob & Tag Kit) is a proximity monitoring system marketed towards iPhone 4S and iPhone 5 users. Proximo consists of two primary pieces -- a keychain fob and a separate tag -- plus one watch-sized battery for each unit, and a screwdriver to make battery insertion and replacement easy. You put the batteries into the units, attach the fob to your keys, and then use a free app to link your iPhone to the fob and tag. The concept is similar to the company's earlier BungeeAir Power, minus the earlier product's battery case.
The Proximo system can track up to four tags at the same time, each with its own customized name, icon, and sound effect; additional tags are sold for $25 each. Kensington expects that you’ll carry the fob around, and should you leave your iPhone behind, the fob will sound an alert; similarly, the iPhone can set off alerts on the fob or tags when you need to find them or if you move out of a designated range. Should you lose something, the app can be used to show you its last-known location for the fob or tag, and provide guidance to that location. The fob and tag can run for up to 6 months on CR2032 batteries thanks to Bluetooth 4; this does prevent them from being used with pre-Bluetooth 4 iPhones, iPods, and iPads, though.
In our tests, the Proximo system worked just as expected. Once you move out of the selected range, the appropriate accessory begins to make noise. It’s worth mentioning that every noise option is incredibly annoying—each one is a grating, synthesized sound, possibly a deliberate design decision by Kensington to help attract your attention. Also important to note: the app has to be running in order to track the fob and tag, either actively or in the background. If you force quit the app, or iOS automatically quits the app to reduce memory usage, the Bluetooth connection will be broken. Perhaps this is why it displays the message, “Check back with Proximo often to keep track of your valuables.” Doing so keeps it running, and the fact that this isn’t purely automatic without the need for user interaction will remain a sticking point for some users. If you’re going to forget your keys or bag often enough to need proximity sensor assistance, you’ll probably forget to re-launch the app, too.
We’re still not sold on the idea of iOS-based proximity monitoring systems being totally practical or necessary, but if you’re in the market for one, Proximo is a fine but somewhat pricey option. The system is simple, and the fob and tag work how they’re supposed to, at least when the app is being used as expected. Hopefully, Kensington will continue to iterate on the idea and come up with even more affordable components, some different sounds, and a practical way to maintain tracking despite iOS’s managed approach to multitasking. For the time being, this merits a limited recommendation, but if the price comes down and the software improves, it might be worthy of more serious consideration.