Ask HN: How can I advertise my open source project for almost no money

It's unlikely open source matters to most of your target market. Any open source advice is typically geared towards developers as users.

Look at competitors products and what people say about them, then see how your project measures up.

I can say from experience, at this early stage, one or two users can give immeasurable feedback. Keep working on the product you want and a few will come along.

Writing posts can help. You want content that can be indexed by a search engine for the permanence. Forum / social / chat posts fade quickly into oblivion

I would change the text on the homepage "StJou - Made for idiots By idiots" and "Let's see how much money you've lost" might be funny but IMHO not appealing for financial data.

Have you done a https://news.ycombinator.com/show post for the project?

I don’t think your audience would care about oss, maybe focus on the free aspect and share it on hacker news show, Reddit, quora, and consider a product hunt campaign and LinkedIn promotion in relevant groups.

You’re going to write about it and link to it from forums your audience visits to learn, if you want to get their attention for free.