Quick Look: Mirror for Roku is only available for Mac users - sorry Windows users. This channel allows you to display your Mac's computer screen on a Roku-connected TV on the same home network. This is done through the use of an app installed on your Mac. You can download a free trial version, or purchase the app from the App Store for $9.99.
According to the developer, the Mirror for Roku is not suitable for gaming because of a 2- to 3-second lag in casting from the Mac to the Roku. However, it should work fine for streaming other video and sound.
-- Information is current as of April 28, 2017
Developer's Channel Description: Application to mirror the screen of your Mac to your Roku. No wires and no additional hardware needed! Connect your Mac without HDMI cables or AppleTV. Download the Free Trial MacOS app by going to: http://bit.ly/TryRoku
CHANNEL STORE CATEGORY: Personal Media
DEVELOPER: AirBeamTV
FEES: Roku channel is free, but requires use of Mac app that costs $9.99 in the App Store
RELATED LINKS:
AirBeamTV Website