Congrats on launching!
Great minds think alike. I also have a similar app (heh, also called "Circles") still in beta at https://testflight.apple.com/join/cwsJZed9
There's also now MinesTRIX from a guy Henri Carnot in France. https://minestrix.henri2h.fr/
Don't let the haters on HN get you down. (Although, hey, you're getting more traction here than I did. Go you!)
But either way, the geeks are not the audience who are going to make or break these projects. I swear half the non-technical people I talk to are very ready for something new. People on HN would be amazed at the hoops that "normies" are jumping through in order to avoid Facebook.
PS - Henri and others (including myself) are working on a spec that would allow these apps to interoperate with each other, letting users on different apps communicate with each other just like with email or Matrix chat. It would be great to have you as part of that effort.