What's neat about the above one is it's a single offline html file that you open in your browser and everything is saved to local storage (but it has a JSON export / import feature for more robust backups).
Of course that means it's really only usable for 1 person, but if you're a solo developer, it's a breath of fresh air to just open a simple html file without needing to run a service to use it.
It's not the prettiest tool but it's very usable. I've been using it to manage a large personal side project. I made a video on that here: https://nickjanetakis.com/blog/an-open-source-and-fully-offl...