The "uncarrier" revolution continues at T-Mobile as the nation's fourth-largest carrier looks to continue luring customers from Verizon, AT&T and -- especially -- Sprint.

T-Mobile has already overtaken Sprint as the top prepaid carrier in the country, a lead it's looking to widen with a new announcement Thursday. The carrier showed off new plans, called Simply Prepaid, which will be available from Jan. 25.

Straight out of T-Mobile's press release, here's a look at what it has on offer:

  • $40 / month for unlimited data, talk and text + up to 1GB of 4G LTE
  • $50 / month for unlimited data, talk and text + up to 3GB of 4G LTE
  • $60 / month for unlimited data, talk and text + up to 5GB of 4G LTE

Sprint's prepaid plans are a little cheaper -- $35 for 1GB of data, $45 for 3 GB of data and $55 for 6 GB of data -- but come with some caveats. For example, video streaming on Sprint's prepaid plans is limited to the carrier's slower 3G networks. And customers get charged overage fees if they exceed their allotment on Sprint.

On T-Mobile, exceeding your data plan won't trip overage charges, although your speed will be slowed way down. Prepaid customers won't get access to some of the perks of T-Mobile's normal subscribers -- namely, the program that exempts any data used by streaming music services from counting against your monthly quota. Users will be able to make calls over WiFi networks.

It's no secret that T-Mobile is gunning to unseat Sprint as the nation's third-largest carrier overall, and that it's coming close to meeting that goal.  Over the summer, T-Mobile chief executive John Legere predicted that it would happen by the end of 2014 -- a challenge that he softened in an end-of-year letter with predictions for 2015.

T-Mobile will - officially - become the No. 3 wireless company in America in 2015. This summer, I said we’d blow by Sprint by the end of 2014 to become the No. 3 wireless company in the US. They have been swinging the bat since I made that statement, so we won’t know where things stand until we get the final score after we both report Q4 earnings, but whether it is now – or soon – I’m telling you, it’s a done deal!

Early reports from Sprint indicate that a late-year rally may let the carrier keep its third-place crown for another quarter, as Forbes reported. But analysts expect T-Mobile to report it's pulled within 1 million subscribers of Sprint when it reports its final numbers for 2014.

T-Mobile has said that, overall, it added 8.3 million customers in 2014, capping off seven consecutive quarters of growth.

Part of its success comes from going after the coveted millennial demographic as it tries to win converts from other networks and become the carrier of choice for young people picking up their first smartphones. In that way, T-Mobile is mirroring moves from companies in other sectors that are responding to the fact millennials aren't huge fans of contracts but still want to get premium goods and services.

And -- at least according to T-Mobile itself -- that plan has been working. "My customers are cool and young. And they're coming, and we're taking over," Legere said last month.