I suggest rereading the page. The app alerts you when your phone has separated from the tracking device. The device is not a GPS device. From the site's copy:

I suggest rereading the page. The app alerts you when your phone has separated from the tracking device. The device is not a GPS device. From the site's copy: "When the Wallet TrackR gets separated from your iPhone or iPad, the Wallet TrackR app gently alerts you that you may be leaving your wallet behind. The app also takes a GPS snapshot of where your wallet was at the moment of separation in case you didn't hear the alert." In answer to your question about the bus, I assume the idea is that your phone will alert you before you get too far (i.e., before you leave the bus). If you managed to leave the bus without catching the alert, the app could tell you where you left the wallet, but not where it's been since then. At least you will know to contact the bus company to see if anything was turned into their lost-and-found.