Google announced that if you conduct a Google search on your iOS or Android device and a site that comes up is built in Flash technology, they will warn the searcher not to click to the site because it would be a bad user experience.
The note reads:
Uses Flash. May not work on your device.
Try anyway | Learn more
Google said this is launching today, and the notice will show when their algorithms detect pages that may not work on their devices. For example, Adobe Flash is not supported on iOS devices or on Android versions 4.1 and higher, and a page whose contents are mostly Flash may be noted.
Google's Pierre Far said on Google+:
If your website still uses deprecated technologies that don't work on mobile devices, it's already well past the time to update it. For example, if a page's main contents (or solely) uses Flash that doesn't work on many mobile devices, starting today we will note that in the snippets in our search results.
So what should you do? Simple: Use HTML(5), JS, and CSS as they are the only technologies widely (and sometimes solely!) supported by all devices. For that, many Googlers have been working on Web Fundamentals to bring you the modern best practices.
Time to upgrade folks.
Google recently began showing faulty redirect notifications in the mobile search results as well.