BLACKorWHITE
Firefox extension for filtering through songs by difficulty on https://spinsha.re/
Legacy code
If you are attempting to run this on a legacy version of the site (for whatever reason), the old version can be built from this commit: https://github.com/LavenderTheGreat/BLACKorWHITE/commit/bf32ccf9ed71edce98db69f4aa3272773a91205e