Question

If a user visits my websites example, from Safari Mobile how could I place there a blank page that says “Add To Homescreen.”? Once added it would show different content.

Answer 1

You’ll want to check two things. First, is it running on an iOS device? Second, is window.navigator.standalone == true?

window.navigator.standalone is primarily used by Webkit browsers to indicate the app is in fullscreen (or standalone) mode. Plenty of devices (like phones running Android), support this property, but don’t have the option to ‘Add to Homescreen’ like iOS devices do, so you need to check both.

Demo:

Javascript:

function isIOS() {
    var userAgent = window.navigator.userAgent.toLowerCase();
    return /iphone|ipad|ipod/.test( userAgent );
};

function isStandalone() {
    return ( isIOS() && window.navigator.standalone );
};

window.onload = function () {
    if( isStandalone() || !isIOS() ) { //either ios+standalone or not ios
        //start app
    } else {
        //display add to homescreen page
    };
};