Allow for simple reason filtering
Using Github API's reason field
https://developer.github.com/v3/activity/notifications/

Do a quick filtering to only show certain type of notification. I am thinking a simple toggle of yes or no to included each type of reason.
ie. I can turn off all the notification except for the one specially @mentioned me
It will be cool to have one of this per repo. There are some repos I want to be notified all the time, others where I only care if I'm mentioned....
I have the same use case as @icatalina
Isn't this an option in Github itself in the "Watch" Menu? Maybe not back in 2017, but today I think this is already possible.

For me, this not a solution because I subscribed via this menu to many repos. I get ~100 notifications per day because I'm interested in the process of these repositories. But I don't want to get macOS notifications via Gitify for all the 100 GitHub notifications (this would be too crazy and I couldn’t work anymore). It would be nice if I could say that I only want for Repo X or when I'm a participant a Gitify macOS notification.
This would be a great addition -- github's notification filtering is poor at best, and being able to do even this thin filtering in gitify would be 💯 .
My specific use case is disabling team mentions so I don't get every PR where the team is left around after auto-assignment to somebody else. There is a setting to disable that, but I don't have control of that.