This month, Google released a new Mobile Friendliness Test tool which can be found at https://search.google.com/search-console/mobile-friendly. This replaces the previous Mobile Friendliness Tool, and has a revamped, improved interface. Google's announcement continues:
Mobile is close to our heart - we love seeing more and more sites make their content available in useful & accessible ways for mobile users. To help keep the ball rolling, we've now launched a new Mobile Friendly Test.
The updated tool provides us with room to continue to improve on its functionality, and over time, we expect it to replace the previous Mobile Friendly Test. Additionally, of course this tool also works well on your smartphone, if you need to double-check something there!
After 2015's mobilegeddon didn't cause quite the stir it was supposed to, Google is doubling down on mobile friendly websites in 2016, an effort that will continue to push non-mobile sites further down the search results. This updated tool is just another signal from Google that they believe Mobile is the future.