An excellent tool for new email notifications, read emails, create emails etc. All info can be found here: https://jasonsavard.com/Checker-Plus-for-Gmail
There is already a request for Gmail notifier and couple more. Please have a look and let us know if these extension cover the same functionality
I have tried several gmail extensions, and found checker plus to be the best for me. It seems others prefer this one too as it has higher ratings with 9944 reviews compared to 564, and over a million users (1,000,418) compared to 152,491. I hope to see checker plus added so I can switch to brave soon. Brave is looking very promising so far. I hope it will have the capacity to add extensions that the chrome web store has to offer.
Request added here https://github.com/brave/browser-laptop/projects/1#card-3546671