Waitlists don't make good HN posts, you can post this when you are ready for people to try it. Some moderator commentary over the years about why that is:

https://hn.algolia.com/?dateRange=all&page=0&prefix=false&qu...

When you're good to go, you could post as a Show HN which is tells people you're posting your own work and are around to talk about it:

https://news.ycombinator.com/showhn.html