FocusWriter for a minimalist, focused writing experience. You can edit the existing template for a dark theme and white text. I rather like the typewriter font, Liberation Mono (it was Courier something back on Windows). Give it a try. I’ve been using it for around 3-4 years.
Tauon Music Box available on Github. You look for albums by typing on your keyboard. Once you see the result which says “Artist”, hit enter. It creates a playlist which shows all the albums of that playlist. The next time you want to listen to that artist, start typing and select “[Artist name] playlist”. This concept differs from playlists, because it doesn’t actually create playlists you can use or export. I just like the UI, although the play controls are bit weird, they don’t quite work the way you’d expect them to.