You add the Google login button to your page with a special option, and then users can log in and specify which device will install your application directly from your site.
This is the most "officially supported" implementation that I know of:
https://developers.google.com/identity/sign-in/web/android-app-installs
From the link:
By adding the Google login button to your website, you can automatically offer your users to download the Android application on the air to their Android devices. To enable this feature, you must use the same Google Developers Console project for your clients on the Internet and Android, as well as configure the login button for the web application.
Your web application should use the Google login button to invite users of your website to download your application the first time they log in. This feature is activated by adding the apppackagename parameter to your login button.
Kirk Elliott Jul 15 '15 at 3:00 2015-07-15 03:00
source share