Trello is super useful and I love it. These are some web extensions I made. I use them almost every day so they should be kept up-to-date as Trello changes how things work. They work in Chrome, Firefox, Edge and Opera.
Lets you tweak a bunch of things that can get annoying if you use Trello regularly.
List Highlighter helps you focus on what you're working on.
Trello boards can fill up with multiple lists pretty quickly. List Highlighter helps you make the important ones stand out. You can change the list background colour, count cards, and break up long lists with headers and separators.
Currently available for Firefox and Chrome
The mobile-optimised pages of Wikimedia sites are often easier to read than the desktop version. With this extension, when you visit the desktop version of a Wikipedia or Wiktionary article (or any article on a Wikimedia site), you will be taken to the mobile-optimised version of that page instead.