how to open Facebook app from url only if installed

Question

I would like to know how to open up a url link from my website in the facebook and twitter app only if it is installed on the device, if not I would like the page to be open

Answer 1

You can try redirecting the phone to opening the app, and if nothing happens, redirect it to the web page you want.

setTimeout(function () { window.location = "https://itunes.apple.com/appdir"; }, 25);
window.location = "appname://";

If the second line of code works, then the first won't be executed.