Mozilla developers additions to the codebase of the mobile browser Firefox Preview (Fenix), which is being developed to replace the Firefox edition for the Android platform. The new browser is built on the GeckoView engine and a set of Mozilla Android Components libraries.
The ability to connect add-ons based on the WebExtension API is available for testing in Firefox Preview. The menu now includes an 'Add-ons Manager' section, which shows the add-ons available for installation. Currently, the only add-on compatible with Firefox Preview listed is uBlock Origin. Support for other add-ons is expected later.
Source: opennet.ru
