Pretty much just the bare minimum note pad alternative. The only real feature is that there are NO FEATURES.
No Right-Click Context Menus No File/Open/Save Options
Technically you can copy from/paste into it, but that's about it. For those times you need a place where you can technically take digital notes, but don't need anyone to be able to do anything else with it whatsoever.
Also because some other less generic notepad apps are a great back door to getting around system restrictions if the user knows what he's doing!