This version doesn’t have a Play Store description, so we grabbed one from version 66.0.2:
Browser using the Gecko layout engine to render web pages, which implements current and anticipated web standards.
Fennec F-Droid is based on the latest version of Firefox. It focuses on removing all of the proprietary bits found in official Mozilla releases. There may still be binaries and the application (or some versions) may be removed or postponed at any time.