T-Mobile releases a SIM unlock app — but for one device only so far

Samsung Galaxy Avant the only phone able to use it

Some big news out of T-Mobile tonight — it's released a SIM unlock app that will allow a phone to work on other GSM networks.

The catch? (Of course there's a catch.) As of this moment, it's only available for the Samsung Galaxy Avant — a low-ender that's just a coupe hundred bucks. (We were able to install it with ease on a couple other phones, including the Samsung Galaxy S5, but unlocking was a no-go.)

There are two options at play here — a temporary unlock, intended for use overseas (which generally is what you want a SIM-unlocked phone for), or a permanent unlock. TMo News earlier reported that the temporary unlock is a 30-day deal, and the permanent unlock will be subject to "certain eligibility requirements."

Of course the usual frequency caveats remain no matter what, so there's that. No word yet if more devices will be able to take advantage of this, but we wouldn't bet against it.

Thanks, Austin!