I’ve updated my Jetpack addon to be a WebExtension add on. It’s been uploaded to AMO as experimental and approved. Its page is here:
https://addons.mozilla.org/en-US/firefox/addon/adlimiter_webextension/
On desktop, this works fine. On Fennec 54.0.1, the web page doesn’t offer an “Add to Firefox” button. Why not? It does have a slider button, which seems to be greyed out or non-functional.
WebExtensions are supposed to work on all Firefox platforms. Unlike with Jetpack, there’s no platform selection in the upload process.