I've just released a new version (1.10.1) that fixes the total not displaying when viewing a list in "grid view"; perhaps that was the problem?

Please try again once the new version is available, and if there are still problems feel free to open an issue at https://github.com/jasontbradshaw/amazon-wish-list-total/issues!

Sorry for the confusion!

For the addon to appear, you'll have to visit one of your Amazon wish list pages, after which it will appear at the bottom left of the screen. You shouldn't need to restart your browser to see it, either.