This one started from me just typing stuff into Claude Code, then adding more ideas and skills / formatting changes as I went until it grew into something useful enough I started telling other people about what it's done for me. Then they asked me to share it so I packaged it up, polished it a bit, and here we are! There's no other editor, I don't use Obsidian or anything with it (although you definitely could). I just find the simplicity of one interface to be really freeing and helps me focus on actually journaling instead of maintaining a card / link system.
It helps me think and reflect across time in a way that my meat mind seems to be not as good at. It's just so fast at searching through things and making associations even with the default Opus 4.6 somewhat limited context. I've ended up capturing and working on so many more of my ideas and I'm so much more inspired on a day to day basis. I hope you enjoy it as much as I do.
It's all on GitHub here, and obviously free and open source: https://github.com/elliotbonneville/claude-cothought