Pocket is a “read-it-later” service that’s built into Firefox. It allows for saving web pages for future reading, and for surfacing articles it thinks you may find useful or interesting. This is good if you’re a Pocket user, but it’s a bit unnecessary for people who have no use for the service. There are two Pocket features in Firefox – a button on the address bar, and a recommended list of articles on the new tab page. Here’s how to disable them both:
Pocket button
Type about:config in the Firefox address bar and hit Enter.

Click the button to “Accept the Risk and Continue”.

Type “extensions.pocket.enabled” in the search bar, and double click the entry to change it to “false”.

If you want to re-enable the Pocket button in future, follow the same steps as above and set the above entry’s value to “true”.
Recommended by Pocket articles
Click the ⚙ icon on the top right corner of the new tab page.

Alternately, you can go to Tools (≡) > Options > Home > Firefox Home Content, or simply type about:preferences#home in the address bar and hit Enter.
Uncheck the option to show “Recommended by Pocket” articles.

If you don’t see this option, it means Mozilla hasn’t rolled it to your location, and you can ignore the above step.
Featured image source: Pocket Icon on Iconscout