“Adblock Edge is a fork of the Adblock Plus(R) version 2.1.2 extension for blocking advertisements on the web.” – from https://bitbucket.org/adstomper/adblockedge/overview
I downloaded it from the Downloads section
Checked the SHA256 hash of the .xpi
mike@mikembp:~/Downloads$ shasum -a 256 adblockedge-2.0.9.xpi ; cat adblockedge-2.0.9.xpi.sha256 5b5b90306cbe675456323fb75d97ac3474315525999e7f7594ce18a7c4a72cd2 adblockedge-2.0.9.xpi 5b5b90306cbe675456323fb75d97ac3474315525999e7f7594ce18a7c4a72cd2 *adblockedge-2.0.9.xpi
Finally opening and installing in Firefox.