Go where the question is already being asked
Somebody, today, is describing the problem your thing solves — in a forum thread, a subreddit, a Discord, a replies tab. Answering that specific person usefully, and mentioning what you built only where it genuinely applies, is the highest-conversion traffic you will ever get.
This does not scale and that is fine. You need a hundred people, not a hundred thousand. Ten good answers a week gets you there in a month.
Submit to the places people actually browse
Directories, launch sites and category listings put you in front of people whose entire reason for being there is finding something new. The traffic is small but qualified, and unlike a forum reply it keeps trickling after you stop working.
Be selective. Five directories your buyers read beat fifty that exist to host links, and the fifty carry a real downside — a footprint that looks like a link scheme.
Ask the people you already know, properly
Not a broadcast post. A specific message to specific people who would genuinely care, saying what you made and what you want to know. Twenty of those produce more usable feedback than a thousand impressions.
What to do with them once they arrive
This is the part people skip, and it is the only part that compounds.
- Tag every source with campaign parameters, so you know which of the above actually worked rather than guessing.
- Watch where they stop. A hundred visitors is enough to see an obvious drop-off, and fixing it doubles everything you do afterwards.
- Talk to the ones who stayed. The sentence they use to describe your product is better copy than anything you will write.
- Only then start on SEO. You now know which problem to write about, in whose words.