Elgato Smart Key

Approximately the size of a casino chip, the Smart Key syncs to an iOS device via Bluetooth, and alerts you when you’ve strayed from the valuable item to which it’s attached. It worked reliably during our testing, pinging our phone when the connection broke, although it isn’t instant, as the phone checks a couple of times to make sure the interruption is genuine. Handily, the dedicated app provides a map of where the connection was lost. However, without a data or GPS connection of its own, you’re unable able to track your valuables if someone else moves them. On the downside, $32 is a lot for such a simple device, and constant use of Bluetooth will impact on your battery life too, but it will be worth it if it prevents you from losing your keys or bag even once.