appStoreRedirect.js

// Simple check so we could use a single button for different mobile OS-s
var operatingSystem, userAgentString = navigator.userAgent;
var link = $("#store");

if (userAgentString.indexOf("iPhone") > -1 || userAgentString.indexOf("iPod") > -1 || userAgentString.indexOf("iPad") > -1) {
    operatingSystem = "iOS";
    link.attr("href", "http://store.apple.com/us/browse/app");
} else if (/Android/.test(userAgentString)) {
    operatingSystem = "Android";
    link.attr("href", "https://play.google.com/store/apps?hl=en");
} else if (/Windows Phone/.test(userAgentString)) {
    operatingSystem = "Windows Phone";
    link.attr("href", "http://www.windowsphone.com/en-us/store");
}