“Instead of full page interstitials, use banners that take up only a small fraction of the screen to grab your users’ attention. These can be implemented in various ways. For example, for app install banners, you can use a browser-supported banner, such as Smart App Banners for Safari or in-app install experience for Chrome. Another option is to create a simple HTML banner, similar to a typical small advertisement, that links to the correct app store for download. You can reuse these small containers for other kinds of notifications, such as newsletter sign-up prompts.” From Google Developers Portal