Excellent initiative, well done!

Do you plan to create such a plugin for Firefox-based browsers? I assume you've chosen Chromium because statistically most users use it. However I believe most people who value their privacy use Firefox (or some fork like Librewolf, Waterfox etc...), it could be great to have access to both .

Other question, do you think it would be possible to add a suggestion to report to Google when a user visits one of the phishing links? This would allow a maximum number of reports, which could increase the chances of getting a “phishing warning” message displayed (for those not using the plugin). I'm thinking of this: https://safebrowsing.google.com/safebrowsing/report_phish/
It would probably be difficult to motivate people to report the phishing link to the hosting provider (often done by e-mail and time-consuming), but reports to Google Safe Browsing are quick and easy.

By the way, I maintain some lists of phishing copies that I frequently report when they remain online (for different websites), if you want I can share it with you from time to time in case there are some you don't have already (perhaps via a PR on Github?).