I posted on HN about Foqos: https://www.foqos.app/ and got a few hundred downloads that same day which is awesome. I still continue to reach out to creators in Youtube and tiktok who have reviewed similar products to see if they would give any feedback. Usually since they have a larger online presence than I do, I noticed the publicly started recommending the app to others on Reddit, Threads, etc...
I've been also posting on threads after each update. I have over a 1000 downloads now, I don't have tracking but getting a consistent download rate of about 30 a day
Zero marketing and its been a ton of fun so far. Hope that helps!