Klip Space - Copy, paste text across multiple devices
VivaldiFox - An add-on that allows colouring Firefox in a Vivaldi style fashion
Multi Copy Paste - Unlock 10 additional copy and paste
automaticDark - Time-Based Theme Changer - Set Firefox to change the UI to a dark theme during the night and change back to a light theme during the day!
Copy Text Easily - Copy Text Easily is a chrome extension that lets you copy text, sentences, or code snippets in a hassle-free manner just with a click.
Dark Reader - Reduce eye strain in your browser with this extension that provides a dark theme for browsing.