Tag My Knowledge - Honest feedback highly appreciated!

I just released the beta version of my new app called Tag My Knowledge (landing page). It's a personal knowledge management tool with a focus on speed & simplicity.

It's available as a Progressive Web App and for Android.

I have so many ideas for extra features and improvements without changing its core, but if people aren't interested, I can't implement them :(

Let me know what you think!

Specific question:
Are the main 4 categories/types too restrictive or just right?