HBO is launching its HBO Go mobile product this week in hopes that letting subscribers watch its movies and original TV shows on the go will help reverse the 1.6 million-subscriber decline at the network and its corporate cousin Cinemax last year.

The new service offers 1,400 HBO titles available through Apple's iPhones and iPads as well as devices running Google's Android operating system. However, the service is only open to consumers with an HBO subscription.

The launch is the latest skirmish between established media and Web players led by Netflix to exploit consumers' appetite for streaming movies and TV. Netflix, launched as a service that delivered DVDs ordered online through the U.S. mail, has ridden the popularity of its newer streaming service to nearly 23 million U.S. subscribers, up from 5 million in mid-2006.

That rise has vexed movie studios, cable system owners and proprietors of premium cable channels like HBO -- and has especially exercised Time Warner Chief Executive Officer Jeff Bewkes, whose company owns Warner Bros. studios and HBO and used to control Time Warner Cable.