That’s why apps to help solve that information gap have been surfacing. The latest one, first picked up by Re/code, is from Brian Roemmele, a digital payments entrepreneur and consultant. Pay Finders, as it’s called, combines crowdsourced data from Apple (AAPL) Pay users, companies, and other sources to show users where they can use Apple Pay.

Apple launched its smartphone-based payments capability more than a year ago, coupled with the release of its iPhone 6 and 6 plus phones. It lets users tap their phone to a payments terminal without having to take out a credit card as their account information is stored digitally.

Though the number of merchants accepting the payments method is growing, users are still unsure when and where they can use it, and as Roemmele tells Re/code, they also forget. The current version of his app aims to help with the finding part of the problem, but eventually he hopes to add location-based notifications to remind users when they’re near a participating merchant.

The reason why there is even a need for apps like this is that Apple Pay isn’t currently available everywhere because it requires special devices on the merchant’s end. Apple Pay—and Android’s own version of the feature—uses a technology known as Near Field Communication, or NFC. Not all payments terminals are equipped with the necessary chip, though a growing number of retailers are switching over. Merchant adoption is actually as important to the success of Apple Pay and its competitors as consumer adoption as the less they’re able to use it, the lower the motivation to purchase a phone with the capability or put effort into using it.

Right now, Pay Finder’s design is pretty basic. When users open the app, they’re shown a busy map of all the Apple Pay locations, though Roemmele plans to add filtering options soon, according to Re/code.

Other such apps include Locator for Apple Pay and Mobile Pay Finder.