Help & troubleshooting for channels on your Roku device, including adding/removing channels, logging in to, authenticating, or activating a channel, channel-specific playback issues, assistance contacting channel publishers to report issues, and adjusting channel-specific settings.
It's possible you've installed it without realizing. Some of the Roku screensavers will have offers to install channels drift across the screen. If you press the OK button to wake the screensaver, or perhaps use CEC to switch the TV on and change to the Roku input, you could install the channel without knowing.
To ensure I never do that, I always use the Home button to wake the Roku, or to switch to it from another input. That ensures I haven't approved something onscreen that I couldn't see.
Dan Roku Stick (3600), Ultra (4640), Ultra (4670), Premiere (3920), Insignia 720p Roku TV, Sharp 4K Roku TV, Nvidia Shield, Windows 10 Pro x64 running Serviio and Plex on a wired Gigabit network.