TL;DR: Per bug 52757 and bug 52759
Currently, [[mw:Extension:MoodBar]] adds a user preference under the "Misc" tab:
- Disable Moodbar
This user preference should either be removed entirely (allowing users to hide the UI with a JavaScript gadget or custom CSS) or moved to the "Appearance" user preferences tab (as the other extensions have done).
Version: unspecified
Severity: normal