KanbanMD is now free I've built a desktop app to use markdown files as trello boards. I thought I'd make it paid to avoid having to handle support for free users (that can get tiring with open source projects), but after seens 0 interest I'm just going to release it for free and see. I use it daily, it's usable, even if not perfect. It's linux only for now. https://kanbanmd.lecaro.me/