How to check if an app is installed from a web-page on an iPhone?

Question

I want to create a web-page, a page that will redirect an iPhone to the app-store if the iPhone does not have the application installed, but if the iPhone has the app instal

Answer 1

To further the accepted answer, you sometimes need to add extra code to handle people returning the browser after launching the app- that setTimeout function will run whenever they do. So, I do something like this:

var now = new Date().valueOf();
setTimeout(function () {
    if (new Date().valueOf() - now > 100) return;
    window.location = "https://itunes.apple.com/appdir";
}, 25);
window.location = "appname://";

That way, if there has been a freeze in code execution (i.e., app switching), it won't run.