A Firefox plugin to optimize Yahoo Mail's layout for smaller screens! Available on the Mozilla Add-ons page. For ad blocking, I recommend using the uBlock Origin extension. The add-on asks for permission to Access your data for sites in the mail.yahoo.com domain and Access your data for mail.yahoo.com, but this add-on does not read any of your emails - it only hides (does not display) the advertisements. The source code for this add-on can be found on (https://github.com/lgsoohoo/yahooScreenSpaceSaver . You can also view the code by right-clicking the "Add to Firefox" button and selecting "Save Link As...". Then change the file's extension from .xpi to .zip and extract the file.