Download here: https://addons.mozilla.org/de/firefox/addon/archive-ph-oneclick/
archive.ph is a web archiving site, founded in 2012, that saves snapshots on demand, and has support for JavaScript-heavy sites such as Google Maps and progressive web apps such as Twitter. It replicates the original webpage including any functional live links. This addon allows easy access to archived snapshots via a context menu.
Very basic web extension for Firefox that adds a context menu to quickly open links in archive.ph.