To Have a universal link setup for android and ios device open app if there else open app store

UnivarsalLinkForAndroidAndIosLaunch-Javascript.js

(function() {
        var getSegment = function (url, index) {
           return url.replace(/^https?:\/\//, '').split('/')[index];
        }

        var App = function(options) {
            this.init(options);
        };

        App.prototype = {
            init : function(options) {
                //Set options in property
                this.options = options;

                //Detect device
                this.device = this.checkDevice();

                // Set username 
                this.username = getSegment(window.location.pathname, 2)?getSegment(window.location.pathname, 2):'' ;

                // Set appUrl and replaceUrl based on device recognised
                this.setAppAndReplaceUrl(this.username);

                this.launchApp();
            },

            launchApp : function() {
                console.log(this.appUrl);
                if(this.device != "WEB") {
                    window.location.replace(this.appUrl);
                    var that = this;
                    setTimeout(function(){
                        that.openWebApp();
                    }, 2000);
                }
            },

            openWebApp : function() {
                var askForStore = confirm("Don't have app? get from store");
                if (askForStore == true) {
                    window.location.replace(this.replaceUrl);
                }
            },

            checkDevice : function() {
                if (/iPhone/i.test(navigator.userAgent)) {
                    return "IOS";
                } else if (/Android/i.test(navigator.userAgent)) {
                    return "ANDROID";
                } else {
                    return "WEB"
                }
            },

            setAppAndReplaceUrl : function(username) {
                switch(this.device) {
                    case 'IOS':
                        this.appUrl = this.options.ios.appUrlSchema + username; 
                        this.replaceUrl = this.options.ios.replaceUrl;
                        break;
                    case 'ANDROID':
                        this.appUrl = this.options.android.appUrlSchema + username; 
                        this.replaceUrl = this.options.android.replaceUrl;
                        break;
                    default:
                        this.appUrl = document.URL;
                        break;
                }
            }
        }

        var app = new App({
            android : {
                appUrlSchema : "myapp://",
                replaceUrl : "https://play.google.com/store/apps/details?id=com.myapp&hl=en"
            },
            ios : {
                appUrlSchema : "myapp:/",
                replaceUrl : "https://itunes.apple.com/in/app/myapp-discovery-app-for/id0001?mt=8"
            },
        });
    })();