All you have to do is download and install the smartphone app, set your preferred range, and the device will send an alert directly to your phone the moment it goes out of range.
Where’s Wallet is beautifully designed by Toronto-based Daniel Eckler, but it may not be to everyone's taste. Also it isn't the only "smart wallet" to offer this functionality. There are plenty of other similar products that include Tvylor, and you don't even need to buy a smart wallet or purse to track your personal possessions. Tracking devices can be purchased separately and attached or inserted into any object, so offer more versatility. Examples of tracking devices worth checking out include TrackR Bravo, Chipolo, Clap-Calp, Gabyls, iMote, Lupo, Moobox O2, Smart Unit, Pebblebee, and Tile.
Three different versions of Where's Wallet are available to pre-order. The "slip model" is available for $49 (£30), the "bi-fold" is $69 (£45), and the "clutch" is $99 (£65). The estimated shipping date is August.