Bing has begun following the steps of Google by launching their own mobile friendly algorithm in the next few months. Bing has explained how they will determine if a web page is mobile friendly by adding a mobile friendly label on your website and what tools they provide to help webmaster ensure your website is mobile friendly.
Bing has been testing the display of a Bing mobile friendly tag in their mobile search results. After receiving positive feedback they will be rolling out a broader label to their mobile search results.
Here is a picture of how it appears in mobile search results:
There is still no set date for this launch; Bing also does not want this update to turn into Mobilegeddon frenzy and give webmasters time to consume this news and look for the right balance between relevancy and user friendly search results.
Late in the summer of 2015 Bing will be launching a new tool to help webmasters analyze webpages and test their website.