Some new software tucked into iOS 9 beta will let T-iPhones play with Apple's Continuity feature over T-Mobile's cellular network, not just over Wi-Fi.
iPad and iOS news
New customers hoping to pay for their tablet in monthly installments and get the free tablet data deal will also need to sign up for a $20-a-month plan.
By giving away data each month, T-Mobile makes a compelling case to buy its version of the iPad. That's dangerous for its rivals.
The carrier is also starting a tablet trade-in program and confirmed that users would get 200 megabytes of data "free for life."
By offering free data, company tempts Apple fans looking to pick up a new iPad Air or iPad Mini with Retina Display.
A check of the Web site had found a requirement to sign up for a monthly plan. Updated: T-Mobile has apologized and called it "an executional mistake."
What to expect if the iPhone officially comes to T-Mobile.
John Legere confirms that the iPhone is coming, a change that promises to lift a shadow long hanging over the carrier. But then there's the LTE question.
The company says the uptake for iOS 9 is the fastest ever for the software that powers its iPhones, iPads and iPod Touch devices.
The new Apple SIM card will let you bounce between carriers on short-term plans, without needing to get a new SIM card.