How cutthroat is the battle between Green Dot Corp. and Bluebird for Walmart banking customers?

So brutal that Green Dot purchased a whole bank — which it relaunched today.

Green Dot launched the beta version of its new mobile bank account, known as GoBank, today. Already known as a provider of prepaid cards, Green Dot is now something its competitor, Bluebird, is not: a bank.

The mobile app is available for download in the iTunes store or Google Play — if you’re one of the few thousand accepted into the beta program.

Green Dot discussed partnering with existing banks, according to Sam Altman, EVP of mobile, but couldn’t find an innovative enough partner. Instead, the company acquired its own bank, the Bonneville Bank, based in Provo, Utah.

A GoBank account has several features to differentiate it from the competition. Users can deposit funds in a savings account called Money Vault as well as the checking account. Users can send money using email, text, social media, or PayPal. Perhaps most uniquely, users can pay whatever they like as a monthly fee — even nothing at all.

GoBank will also contain a Fortune Teller, a humorous feature in the app that will check potential purchases against account balances and let the user know if it’s stop or go on the wanted item in a lighthearted way.

Green Dot continues to accept deposits at Walmart checkout counters, and hopes to expand its retail network. Green Dot, having no branch presence of its own, taps into a network of 40,000 fee-free ATMs, and also provides mobile remote deposit capture.

The company has taken a hit since Bluebird has gobbled up shelf space at Walmart, and nonbank competitors have arisen to to challenge the company’s position. Will being a real bank win the day for Green Dot?