Last year, Amazon made it possible for Fire TV Cube customer to use hands-free voice commands to navigate within select apps. This made it possible to make selections and scroll around apps like Netflix and HBO without needing to use a remote. A recently published developer page about the new feature states that Amazon will “be enabling this feature on other devices in the future” and “will extend these capabilities to all apps.”

Currently, only the Fire TV Cube can use voice commands to navigate within apps. This is uniquely different from using voice commands to play content and control media playback within 3rd-party apps, which all Fire TV models are capable of doing. In-app voice navigation essentially allows you to mimic the directional circle buttons on a Fire TV remote, including the select button, with your voice. Saying “Alexa, move/go [direction]” simulates a single directional button press, while saying “Alexa, page/scroll [direction]” simulates pressing a directional button multiple times in a row to move more quickly across an app. Saying “Alexa, select” simulates pressing the center select button of the Fire TV remote.

I presume that once in-app voice navigation comes to other Fire TV devices, it will be available through an external Alexa device, like an Amazon Echo or Echo Dot, however, the developer page does not specifically mention that to be the case. It would be completely useless to enable the capability only through the voice remote, since, if you’re already holding the remote, you’d clearly have no use for voice navigation.

When in-app voice navigation first launched on the Fire TV Cube, it was initially only available on 17 apps. I don’t know if that number has increased since, but the Amazon developer page states that: “In-app voice scrolling and navigation will be rolled out in phases to select apps. Over time, Amazon will extend these capabilities to all apps.” The page also states that games will not receive in-app voice navigation capabilities.

There are several characteristics of apps that will never receive voice navigation support. These primarily include apps that behave unpredictably when they lose input control, which is also refered to as “focus.” For example, if the currently highlighted item in an app changes or moves when the Alexa voice overlay appears at the top of the screen, it would render voice navigation useless, so those apps will never be whitelisted for the feature.

Something that’s important to know for all app developers is that once an app gains in-app voice navigation support, it can never lose it. This means that if an update to an app breaks voice navigation, the update will not pass Amazon’s app review process. App developers can choose to opt-out of in-app voice navigation altogether if they prefer not to have to maintain this kind of support. App developers may also request for their app to be whitelisted early if they feel the app works well with the feature.

Amazon will control which apps get whitelisted for in-app voice navigation. They say they will “start with media apps and extend coverage to other categories on an ongoing basis.” One reason for the slow rollout, apart from having to confirm each app works with the feature, is that Amazon will be customizing specifically how many directional presses will be executed when a customer gives the scroll/page command. For example, in the Netflix app, there are 5 thumbnails displayed in each row of content. Saying “Alexa, scroll right” in Netflix on a Fire TV Cube causes the entire row of 5 items to slide off screen, revealing 5 more items. This behavior was customized by Amazon for the Netflix app because the default scroll quantity for horizontal in-app voice navigation is 3 elements.