After betas, Firefox 38.0.5 final has been released and available. Mozilla has added Pocket (formerly known as Read It Later) and Reader View features. After installing this version, you’ll notice a new Pocket icon in the toolbar, You’ll find it in other places in Firefox like Bookmarks menu, Context menu as ‘Save page to Pocket’ (this appears after signing into Pocket website). You can disable or remove both Pocket and Reader View features by following the below steps.
Disable or Remove Pocket and Reader View features from Firefox 38.0.5
For Pocket thing
UPDATE: The easiest way to disable pocket is removing its icon from Toolbar or Menu using customize dialog, then View pocket list in Bookmarks menu gets disappear as well. Try and let me know.
1. Visit about: config
2. Find browser.pocket.enabled preference and change its value to ‘false’.
3. To remove Reader view, change reader.parse-on-load.enabled preference value to ‘false‘.
4. Restart the browser to see the changes.
Do you (the user) or Firefox browser really need these features?