Reader Mode (Firefox for Android)
In the Android version of Firefox, Reader Mode will reformat a page to make it more readable on the smaller screen of a mobile device. If Firefox determines that it can do this upon fully loading the page, a book icon will appear by the URL bar -- tapping this will extract the main text in the page you are reading, enlarging its font, and stripping away the other elements in the layout. However, with many sites that did not have mobile versions, Reader Mode would not trigger on. When it is available and you activate it, you cannot pinch-and-zoom in on a re-formatted page -- instead you enlarge (or shrink) text through a settings toolbar along the bottom of the browser.