document.addEventListener('deviceready', function() {
    var exitApp = false, intval = setInterval(function (){exitApp = false;}, 1000);
    document.addEventListener("backbutton", function (e){
        e.preventDefault();
        if (exitApp) {
            clearInterval(intval) 
            (navigator.app && navigator.app.exitApp()) || (device && device.exitApp())
        }
        else {
            exitApp = true
            history.back(1);
        } 
    }, false);
}, false);