Isis Mobile Wallet, the mobile payment joint venture from AT&T, T-Mobile and Verizon, rolls out nationwide today.

Isis uses NFC technology in phones to enable tap-to-pay functionality with mobile devices at participating retailers. The Isis app is free to download from Google Play but users will need to get a new SIM card from their carrier.

The national release for Isis follows extensive market testing of the technology in Austin, Texas and Salt Lake City.

As revealed at MobileCon in San Jose, Jamba Juice today starts a one million smoothie giveaway promotion for Isis Mobile Wallet users. AT&T announced that in addition to its support of Isis and the secure SIM needed, the carrier is also now accepting Isis Mobile Wallet payments in its retail stores.

Chase Freedom, Sapphire and Slate, as well as JPMorgan Palladium cardholders can load their card info into the secure element of their devices.