Launch an android app from Ionic app

I have been trying to open an android app from an Ionic app. for That i have downloaded com.lampa.startapp plugin. I am calling an android app on a button click. but i am getting an error in my console saying that Cannot read property ‘start’ of undefined

following is my controller

.controller(“TestCtrl”, function($scope, $cordovaInAppBrowser){
console.log(“test ctrl called”);

$scope.submit = function(){
	console.log("submit function  called inside TestCtrl");
	navigator.startApp.start("com.myapp.demo", function (message) {
            /* success */
            alert(" navigator called");
            alert(message);
        },
        function (error) { /* error */
            console.log(error);
            alert(error);
        });
}

})

Can anyone please help me to figure this out? any help would be much appreciated.