The new feature can switch Roku TVs on or off and change channels with spoken commands. You can also adjust the volume by saying "Alexa, turn up the volume on Roku." Quite a mouthful, but certainly useful if you don't want to be bothered finding the remote. You can also ask the voice assistant to search for entertainment ("Alexa, find [shows] on Roku"), pause your device ("Alexa, pause Roku") and launch particular apps (e.g. "Alexa, open Hulu on Roku).

To be able to access the feature, your Roku devices must be running OS 8.1 or greater. If they are, then fire up your Alexa app, select TV & Video under settings and enable the skill to link your accounts.