This bool is true if the user has clicked the website on tablets, smartphones etc..

MobileDeviceBoolean.js

var mobiledevice = ((typeof window.orientation !== "undefined") || (navigator.userAgent.indexOf('IEMobile') !== -1));

if(mobiledevice){
//do something different
}

// OR use  the maxTouchPoints-method

mobiledevice = navigator.maxTouchPoints > 0;

if(mobiledevice){
//do something different
}