The alternative add-on recommendations feature on addons.mozilla.org (AMO) is intended to help ease the transition to WebExtensions add-ons in Firefox 57. The feature will work by showing users recommended replacements for legacy add-ons that do not make the transition. This feature won’t launch until some point close to Firefox 57, because we want to give legacy developers enough time to transition before showing alternative choices.
We’ve already begun compiling new WebExtensions add-ons in this page and mapping them to legacy add-ons they might replace. There’s been interest in the community to help with this effort, so we invite anyone who knows of other great WebExtensions content to please feel free to note them here in this thread. Myself or another admin will add appropriate titles as we go. Thanks in advance!