Now that unlocking your phone is legal in the United States, carriers have no choice but to let you use your device with other service providers as soon as your contract is up. T-Mobile is preparing to make it super simple for you to do that by pre-installing an unlocking app on your device that will remove its shackles as soon as it is eligible.

TmoNews has obtained images of a new “Device Unlock” app pre-installed on a Samsung Galaxy Avant test unit which gives owners the ability to unlock their handset without having to contact customer care.

It actually provides two unlock options: There’s a permanent unlock for those who want to free their handset from T-Mobile for good, plus a temporary one which lasts for 30 days and is ideal for those who wish to use their device with another carrier only while they’re on vacation abroad.

If you choose the permanent option, the app will check your device is eligible for unlocking and then presumably perform the process. The screenshot obtained by TmoNews, however, shows the unlock failed on this particular handset because it is still tied into a T-Mobile contract.

It’s thought a temporary unlock may not have the same restrictions, and that customers may be able to use it while tied into a contract — maybe a certain number of times a year — so that they can take their device abroad and use it on other networks only while they’re away.

The Device Unlock app is pre-installed on regular, publicly available Galaxy Avant handsets, according to TmoNews, and is likely to make its way to other new devices in the future. It will reportedly only be available as part of T-Mobile’s pre-installed software package, and not as a download through Google Play.

• SourceTmoNews