Google uses HTTPS and SSL as a ranking signal in their search results. This means that using HTTPS and SSL will help improve your site’s SEO.
more to come....
For websites not optimized for multiple screens, it will only get worse. Google has more of an incentive to continue to update search results for mobile searchers, as they recently announced that there are officially more smartphone than desktop searches in the U.S.
TEST YOUR SITE
This test will analyze a URL and report if the page has a mobile-friendly design.