PowerKeys от kyu

This extension gives you advanced functionality for the candykeys.com website.
Some of the features include:
- Hide items that are out of stock or only for preorder
- Sort items based on their price, name or rating
- Dark mode
- Draw borders around images for better accessibility
- Convert EUR-prices to other currencies

It's also open source: https://github.com/kyunal/PowerKeys

Regarding the permission for "api.coinbase.com":
The Coinbase API is used to get exchange rates for currencies as it does not require any form of authentication. It is necessary for the add-on to declare this permission in advance.
If you do not opt-in to use the currency conversion feature, no data is ever sent.
If you do opt-in to use this feature, no personal data is sent, but their privacy policy applies: https://coinbase.com/legal/privacy

Current Version: 1.3