unless you're the same guy from before, an idea like this was proposed to me earlier today, except in reverse (they wanted the most commonly used relays of people who follow them)
i use Damus as well, but i must admit that a little web tool (such as the one i recently made at https://nrcheck.tigerville.no) would probably help more people. i'd just make it so you could paste your npub there and it would scan everything and that would work no matter what client you have.
Discussion
That was not me, and that sounds interesting as well. Agree a web version of such a tool will reach the most people.
The lowest friction experience for iOS users I think would be in app.
Looking forward to playing with the app when ready.