Device Unlock, the new app that will allow T-Mobile customers to quickly and easily unlock their smartphones when their contract is up, is now available to download from Google Play. You probably won’t be able to use it just yet, however, because it seems it’s initially only compatible with just one handset.

We first learned about Device Unlock on Thursday when TmoNews acquired screenshots of it running on a Samsung Galaxy Avant test unit. Its purpose is to provide users with a simple, permanent unlock method so that they can use their handset on other GSM networks when their contract is up.

It also provides a temporary, 30-day unlock solution that will be useful for those looking to use their handset on another carrier for a short period while they’re in another country. The permanent one won’t work unless your contract with T-Mobile has ended, but the temporary one will — presumably with some restrictions that are yet to be confirmed.

It was initially thought that Device Unlock would only be pre-installed on future T-Mobile devices and not available through Google Play — but now it is clear that won’t be the case. The app is today available to download, but although it will install on a number of devices, it will actually only work on the new Galaxy Avant.

That’s expected to change later, but for now, you’ll have to wait. T-Mobile is thought to be testing the service with a small number of customers before eventually opening it up to everyone.

• Google Play StoreDevice Unlock