I built Userdoc (https://userdoc.fyi) a requirements management system for software projects.
After running a development consultancy for 8 years, I wanted a dedicated system for gathering and confirming requirements, and only syncing them with project management tools like Jira when they are ready (but keeping them in Userdoc as the living documentation and source of truth.
Things are going well, we have some large enterprise and government clients - and a two week experiment with AI back in January has lead to infusing AI into most aspects of the platform, which has opened up a lot of doors.