Google has just announced that the HBO Now streaming service is coming to Android TV, Chromecast, and Android, following an exclusive launch period on Apple's devices.
Coming next month
HBO Now is HBO's stand-alone streaming service that requires no cable TV subscription. It is available for $14.99 per month. Besides that you just need internet and a device that supports HBO Now.
Until now, HBO Now has been available only on Apple's devices such as Apple TV as part of an exclusive deal. That will end soon. Google announced at I/O 2015 that HBO Now is coming to Android TV, Chromecast, and Android.

"Android TV" devices currently include 2015 Sony, Sharp & Philips' TVs as well as media streamers such as Nexus Player and the Nvidia Shield box.
No exact launch date was disclosed, only "this summer", but Google adds that it will be online in time for the new True Detective season (June 21st).