I launched howtoconvert.co about 3 months ago now. It's a universal file converter app that converts almost any file to any other file locally. This week I crossed 500 paying users.

Here's why I think it did well:

Solved a real privacy issue (local file conversions, no server uploads).

Built an easy drag-and-drop UI for non-techies.

Posted about it transparently (just like this post!) on hackernews, reddit and threads. I don't have a big enough following on other sites to get any views there yet.

Others out there building projects: if your last project failed, remember that solving a simple, common problem and sharing your journey openly can make a big difference.

You don't need to make a new "facebook" for this or "uber" for that. Just something to help solve a simple problem.

Keep building and learning!