HBO said Monday its stand-alone streaming service, which will deliver sought-after television shows such as “Game of Thrones” to people who aren’t cable subscribers, will at first launch exclusively to customers using Apple devices.

On April 1, Apple customers will gain access to current HBO shows for $14.99 a month in a three-month exclusive arrangement between the two companies. The service, HBO Now, will be available on the iPhone, iPad, iPod touch and Apple TV. Viewers can also watch on their web browsers on PCs or Macs, but they will have to sign up first through an Apple HBO Now app downloaded through an Apple device. A cable or satellite subscription will not be required to access the online content.

By allowing access only to Apple customers at first, HBO may limit the risk of consumers canceling their cable services en masse. Several television networks, such as ESPN, CNN and the Food Network, are also offering their services online through Dish's Sling TV streaming service. CBS and Showtime also offer streaming-only services. But for consumers hoping to drop their cable bills, paying for a slew of separate streaming services could prove expensive when all the costs are added up. Sling, for instance, is $20 per month.

The HBO announcement was made during Apple's product event in San Francisco, where the first guest presenter was HBO chief executive Richard Plepler.

“HBO NOW is the next phase of innovation at HBO,” Plepler said. “With this new partnership, a natural evolution for the network, we have access to millions of Apple customers who are used to getting their favorite apps immediately. Now, they can do the same with an HBO subscription.”

HBO said it is still negotiating with other partners for online distribution. Analysts have said that moving online could quickly undo the cable bundles that have been a staple of television viewing for decades.

The online service is the same price that cable subscribers typically pay for HBO on top of basic service. And HBO probably will take a much bigger cut of streaming revenue than it does from partnerships with cable operators. But it will be harder for HBO to keep consumers from sharing their passwords with each other to save money, said Laura Martin, an analyst at Needham & Co.

"It's a hugely risky trial for HBO because online is a world where lots of people share passwords and that means they can lose money on each of those trades," Martin said.