Any recommendations for a self hosted note taking app that runs on everything with a screen and is designed for multi device usage?

Also a modern, powerful and puristic UI would be a must have to compete with Keep.

I am looking for this app every now and then but am always disappointed by the choices.

I recently tried Joplin on Android, but was very dissatisfied with the usabilty.

The FOSS self hosted alternatives for smart home and porn are better than the commercial ones, can't be that hard for notes, can it?