I created this app because I found myself a bit overwhelmed with Notion's complex and rigid databases (especially their kanban view), while also thinking that Google Keep was not structured enough for my needs.
Zenkan is a bit in the middle, I tried my best to add a nice drag-and-drop feel to it (also some satisfying sounds) while enforcing a nested structure for the cards. Zenkan can serve both as a Kanban for tasks and as a way to group related notes in a very visual way.
Let me know if you have any questions or suggestions!