JDex Manager
Johnny.Decimal inside Obsidian, with the index as the system.
What it is
JDex Manager starts from one idea: in Johnny.Decimal, the index is the system. The plugin creates and maintains the JDex notes and checks that folders and IDs still line up.
How it's built
TypeScript on top of Obsidian's vault API, with no direct filesystem access -- which is why it also works on iOS and Android.