Back in April, Mozilla added five Extensions to Firefox Preview, today in the month of June, the company added three more recommended extensions –Decentraleyes, Privacy Possum, and YouTube High Definition – to the Nightly version.
In October last year, Mozilla confirmed Fenix will support Extensions, but said, it will gradually release few extensions from the Recommended Extensions Program. The company in February added Ublock Origin and in April, it has added five extensions named Dark Reader, No Script Security Suite, HTTPS Everywhere, Privacy Badger and Search by Image to Firefox Preview.

The total number of extensions Firefox Preview supports became 9 now with the addition of three new extensions:
Decentraleyes. Here is what this extension does:
Protects you against tracking through “free”, centralized, content delivery. It prevents a lot of requests from reaching networks like Google Hosted Libraries, and serves local files to keep sites from breaking. Complements regular content blockers.
Privacy Possum. Here is the description of this extension
Privacy Possum monkey wrenches common commercial tracking methods by reducing and falsifying the data gathered by tracking companies.
YouTube High Definition. Here is a little brief about it:
YouTube High Definition is a powerful tool that automatically plays all YouTube videos in HD, changes video player size, offers auto-stop and mute, and much more.
You can find all these extensions in Firefox Preview Nightly, which you can download from Play Store here.
To add one or more of the above extensions
1. Launch Firefox Preview Nightly
2. Tap on menu icon and select Add-ons
3. Tap on + button that appears opposite to the extension, the Extension will be installed.
Similarly, you can add other add-ons that appear under the “Recommended” section to Firefox Preview.
Related articles:
Mozilla confirms Firefox Preview for Android will support Extensions
Mozilla adds Five more extensions to Firefox Preview Nightly
Firefox Preview for Android receives UBlock Origin Support, here is how to install it
Firefox Preview 5.2 for Android now available on Play Store
Firefox Preview Beta for Android gets Voice Search and more