You can also try these related scripts:

• Direct links out - Removes all "You are leaving our site" and redirection stuff from links
• Switch Slack channels. - Use ALT+PageUp/PageDown to navigate Slack channels.
• Silence Slackbot - Silence SlackBot
• Get lost giphy! - Remove giphy from slack
• Add video player to Slack - Adds a HTML5 video player when it senses a video file.