Southwest became the first U.S. airline to enable passengers to text on their flights from gate to gate.

The initial implementation enables passengers to connect their iPhones to onboard Wi-Fi and use iMessage for texting at an introductory $2 fee. They would have to text to other iMessage users, and the service works on devices using iOS 5 and later.

If passengers want to text and use other onboard Wi-Fi services, which are satellite-based, they pay the standard Southwest Wi-Fi fee of $8 per device.

Android-related texting services will be added in 2014, Southwest says.

The iMessage texting services comes through a Southwest’s ongoing partnership with Global Eagle Entertainment. Its subsidiary, Row 44, provides Southwest with satellite-based Wi-Fi.

The services are available on 435 Southwest aircraft. With satellite-based Wi-Fi, Southwest is currently the only U.S. airline to offer Wi-Fi below 10,000 feet.