Today is the day – 21st April 2015 – when search engine results will never be the same again. It’s official, Google will promote mobile-friendly sites which means that if your 
site doesn’t pass the mobile friendliness test, then it will feature less prominently on its search engine results.
In a blog post, the company has stated that “Starting April 21, we will be expanding our use of mobile-friendliness as a ranking signal. This change will affect mobile searches in all languages worldwide and will have a significant impact in our search results. Consequently, users will find it easier to get relevant, high quality search results that are optimized for their devices.”