As we know, Google is strictly against the interstitials (usually seen on mobile devices promoting a website’s native app, sign-up forms, or advertisements,
can make for a bad user experience).
From November 1, Google will no longer consider sites with interstitials ‘mobile-friendly’.
Google explained this on its Webmaster Central Blog:
After November 1, mobile web pages that show an app install interstitial that hides a significant amount of content on the transition from the search result
page will no longer be considered mobile-friendly.
Here’s an example of what Google is talking about,
Currently, when you search for a site in your mobile device, google shows this site as google friendly, but if site does not removes the interstitial that promotes his apps, Google will no longer consider it as mobile friendly
Google offers an alternative in the form of app install banners, as shown below:
Instead of app download interstitials, Google reminds that browsers promote apps in ways that are more user-friendly.
These banners don’t obscure the content, yet offer the chance for users to either interact with them or close them down. Google’s mobile-friendly testing tool has been updated to reflect this announcement.
You will also get a warning in Google search console, if it detects large app download interstitials
Google will no longer consider these sites as mobile friendly, and you will see the impact on traffic.