Colorful, simple and 'unified' UI: no need to navigate between screens;
Expandable bottom panel containing the player controls and the settings (if expanded):
Played song info: clicking on it You can open the played Artist's page/album or open/close the Artist's page You're exploring (when not playing). The text is scrollable on long click;
Skip to previous song (long click to enable reset 1x);
Play/pause;
Skip to next song;
Music organized by Artist (the Artists names are scrollable on long click);
'Revealable' Artist's page: albums + songs (the selected album title and songs titles are scrollable on long click);
Colorful alphabetic scrollbar;
Search bar (which can be disabled);
Dark status bar icons (available from Android Marshmallow);
Settings at hand:
Dynamic shuffle button: randomly plays the device or the Artist songs (when the Artist's page is 'revealed');
System equalizer (if present on the device);
Themes (light and inverted);
Search bar visibility;
Link to git page;
16 awesome UI accents!;
Other features:
Pause/resume when the headsets are (dis)connected;
Simple audio focus (notifications, calls, or other media apps) management;