No nah nope. You don’t need an app for this. You need the classic hierarchical file system and good folder and file names. I put it all in a VeraCrypt volume so it’s secure if the device is lost or stolen.
1. Make your own according to your own needs (what I do).
2. Copy one of the other comments here.
3. Something yet more structured like https://johnnydecimal.com/
Such as?