This project is now defunct as filtering has been added to the site.
A simple Firefox extension that allows you to a view grade range for a crag while not disrupting the locations.
If you would like to try running locally or modifying try the following steps.
git clone git@github.com:aaaaargZombies/ukc-grade-filter.git
npm install
Install web-ext if you don't have it already
npm install --global web-ext
Run webpack and web-ext
npx webpack -w
web-ext run --verbose --start-url https://www.ukclimbing.com/logbook/crag.php\?id\=104