This is not a great day for developers of the various third-party Roku apps available at the Windows Store. It's an excellent day, however, for those who've been waiting on a free remote control app direct from the company itself. The app is compatible with Windows Phones as well touchscreen Windows 8 and RT tablets, but it's not designed for mouse n' keyboard setups. Just like the iOS and Android versions, it'll scan your network and (hopefully) find all your players and channels, at which point it'll act just like a regular remote, although it does appear to be missing the new enhanced search function found elsewhere. One other thing you might find lacking is the ability to stream your own choice of web files (.mov, .mp3 etc.) to your Roku box -- you'll still need an unofficial app for wild stuff like that.
Microsoft Windows 8
Microsoft Windows Phone 8.1