It's been nearly three years to the day in the making but mobile wallet service Isis has finally launched nationwide. It arrives with support from three of the nation's top four wireless carriers and will allow those with NFC-enabled smartphones to make mobile payments anywhere the service is accepted.

The initiative is jointly operated by AT&T, T-Mobile and Verizon Wireless and is now available for a number of smartphones. With the app, customers can simply wave their phone at a wireless payment station to initiate payment for things like gas, sodas and even cab rides.

The idea of a digital wallet is nothing new as others like Google Wallet and PayPal have been at it for some time now. Even with heavyweights like Google and PayPal in the mix, however, the technology hasn't really taken off with consumers for a number of reasons. Apple's iPhone doesn't ship with NFC technology and it probably won't anytime soon, either.

But Isis isn't put off by the lack of consumer interest and instead, are hoping to drum up their own interest with some special incentives. Isis Mobile Wallet users can now use My Coke Rewards and Isis to score three free drinks at select vending machines. Jamba Juice, meanwhile, is giving away 1 million free smoothies to Isis users while those using their American Express Serve account with Isis can enjoy up to 20 percent off purchases (up to $200).

Those interested in trying Isis will need a special enhanced SIM card and will either need to snag the app from Google Play or sign up at a retail location for their wireless provider.