We’ve heard of the ways that the smartphone can supposedly replace our wallet, but that doesn’t seem to have happened yet. In the meantime, what if our smartphone could simply help prevent us from losing our actual wallet?

That’s what Wallet TrackR, from a company called Phone Halo, purports to offer. Here’s how it works. First, Wallet TrackR hooks you up with what it says is the “world’s thinnest Bluetooth device, about the size of a credit card.” You can probably already see where this is going. You slip that Bluetooth credit card thingy in with your wallet, and pair it with your iPhone (Wallet TrackR also has an app). If your wallet and iPhone become separated, the app records the GPS coordinates of where the phone or wallet was left.

There’s undoubtedly a market for this. Today I stepped on the subway in Brooklyn, as multiple people stepped off. As the train pulled away, one of the women on the platform moaned as though she’d just seen a loved one abducted. People turned to look at her in concern, as the train began to pull away. “I can’t find my wallet!!” the woman screamed.

Perhaps that was an overreaction, but the truth is that a lost wallet can mean not only the loss of cash and the risk of identity theft, but also the hours spent cancelling some cards, while renewing and replacing other ones.

It can also help you out with more banal, everyday forgetfulness. Sometimes you step out of the house without realizing you left your wallet–safely, but annoyingly–at home. “Never again will someone have to face the embarrassment of being out with friends or on a date and having to confess they forgot their wallet,” Phone Halo co-founder Christian Smith said in a press release. “What’s exciting here is that we are helping consumers to prevent loss or misplacement in the first place by alerting them before they have stepped away from a valuable item.”

The service is as much preventive as restorative, in a way.

Wallet TrackR isn’t on the market just yet; Phone Halo has set up a crowdfunding website to help tip the device into wider production. How do you know you can trust Wallet TrackR to actually get made? Phone Halo points to former success, including Cobra Tag, a 2011 device that could track your keys from a smartphone. These guys have expertise in digital lost-and-found.