Bing announced the release of their mobile friendliness test tool today. This was promised to us back in May 2015, when Bing told us they were working on a mobile-friendly Bing ranking algorithm. It was actually expected in the late summer but was delayed.
The tool evaluates a page to check if it is mobile-friendly based on these criteria:
Here is a screen shot of the tool in action. As you can see, it shows a preview of the site on the right side:
Bing has not yet announced the launch of their mobile-friendly algorithm; that may come soon.
Google launched their mobile-friendly testing tool just about a year ago today.