New: Draw.io (Jun 2, 2022), Platform 22.0b1 (Jun 10, 2022)
400+ real apps (47GB), 1.04 billion downloads, Please donate.
This app would be nice to add.
At least, you may try the already present ones: KeepNote & Cherrytree. There is also another one → https://treeline.bellz.org/
Be Great or Be Quiet !