The simple UI plugin is a game changer.

I just installed it last month myself. It really makes KoReader feel much more modern

the improved UI literally is so appealing that i find myself reaching for my kindle way more then i used to on stock KOReader. It is awesome to pair with the (2) plug ins below: https://github.com/Euphoriyy/appearance.koplugin (give Simple UI a background!) https://github.com/pxlflux/customisablesleepscreen.koplugin/ (beautiful sleep screen with a ton of customization!)