This addresses email notifications only. There is a lot of apps that would send you notifications that you want to see like your hardware needs attention but also sends some useless promo notifications
I would pay a lot to have this on iPhone as I'm distracted easily due to my ADHD. iOS doesn't have as granular notification configuration as Android (topics?) plus Apple probably wouldn't agree to funnel all notification through 3rd party app.
Those are good tips but what to do when you are new in location and your family/friends doesn't have contacts with people that like your hobby? Joining new social circles isn't that easy for less social ones.