Mozilla is working to bring Reader mode of Firefox in Android for desktop, it has now reached alpha stage, the team working on this project has showed demo through a video. With Reader mode, you can view and read articles in minimalist UI without any distracting elements on screen in Firefox.
For more information on this, read Desktop Firefox to get Reader Mode of Mobile’s
Here is how Reader mode in desktop Firefox supposed to work and its progress so far
If a page detected as reader-friendly, then Reader icon (book) will appear in the location bar, which, when clicked pop up window comes up and that window will be filled with article content on the same tab stripping out unnecessary elements on the page. User can navigate back to the original article by click on the back button.
Reader mode has dedicated about:reader page, which loads page content when user clicks on the ‘Reader’ button. This page allows user to change font, text sizes and offers dark and light modes for reading.
Reader mode has a preference reader.enabled, which when turned on, always shows the reader button on the location bar. Reader mode for Firefox uses same font OpenSans which mobile version uses.