

/cdn.vox-cdn.com/uploads/chorus_image/image/52902459/focus-firefox.0.0.png)
This is useful for the webpages that check your visibility state before loading resources like many music webpages. By installing this extension a small script is injected into every webpage which overwrites the "document.visibilityState", and "document.hidden" properties to pretend the tab is always in the active state (document.visibilityState = 'visible' and document.hidden = false). Some websites use this track to only offer services when the tab is active. This extension protects against web pages tracking the activity state of the page.
