The provided app differs from another app with the same version and product id sharepoint 2013 (Sample 1)

I solved it by increasing the version number in the AppManifest
Previously - It was Version 1-0

Create new item in custom list using JSOM sharepoint 2013

https://www.dropbox.com/s/r5q3j5s1fv6yxsb/TravelSystem.rar

1) Add your site URL in properties

2) Run Project

Sharepoint 2013 Getting List Items using JSOM – Sharepoint-Hosted Application

1) Create Custom List in Sharepoint 2013(Office 2013 Account )

2) Copy & Paste below code in your App.js and deploy application

3) App.Js

// context: The ClientContext object provides access to

//      the web and lists objects.

var context = SP.ClientContext.get_current();

//Get the URI decoded SharePoint site url from the SPHostUrl parameter.

//https://XXX.sharepoint.com/TravelApp

var hostUrl = decodeURIComponent(getQueryStringParameter("SPHostUrl"));

//https://XXX.sharepoint.com/TravelApp/TravelSystem

var appweburl = decodeURIComponent(getQueryStringParameter("SPAppWebUrl"));

var hostcontext = new SP.AppContextSite(context, hostUrl);

var web = hostcontext.get_web();

var lists = web.get_lists();

$(document).ready(function () {

    var scriptbase = hostUrl + "/_layouts/15/";

    $.getScript(scriptbase + 'SP.Runtime.js',

    function () {

        $.getScript(scriptbase + 'SP.js',

       function () {

           $.getScript(scriptbase + 'SP.RequestExecutor.js', execCrossDomainRequest);

       });

    });

});

function getQueryStringParameter(paramToRetrieve) {

    var params =

    document.URL.split("?")[1].split("&");

    var strParams = "";

    for (var i = 0; i < params.length; i = i + 1) {

        var singleParam = params[i].split("=");

        if (singleParam[0] == paramToRetrieve)

            return singleParam[1];

    }

}

function execCrossDomainRequest() {

    var context;

    var factory;

    var appContextSite;

    var mylist;

    context = new SP.ClientContext(appweburl);

    factory = new SP.ProxyWebRequestExecutorFactory(appweburl);

    context.set_webRequestExecutorFactory(factory);

    appContextSite = new SP.AppContextSite(context, hostUrl);

    this.web = appContextSite.get_web();

    mylist = this.web.get_lists().getByTitle('Test');

    var camlQuery = new SP.CamlQuery();

    camlQuery.set_viewXml('<View><RowLimit>10</RowLimit></View>');

    var collListItem = mylist.getItems(camlQuery);

    context.load(mylist);

    context.load(collListItem);

    context.executeQueryAsync(

     Function.createDelegate(this, successHandler),

     Function.createDelegate(this, errorHandler)

    );

    function successHandler() {

        var listItemInfo = '';

        var listItemEnumerator = collListItem.getEnumerator();

        while (listItemEnumerator.moveNext()) {

            var oListItem = listItemEnumerator.get_current();

            listItemInfo += "<li style='height: 20px;'>" + oListItem.get_item('Title') + "</li>";

            document.getElementById("message").innerHTML = '<h1>' + mylist.get_title() + '</h1><br />';

            document.getElementById("message").innerHTML += listItemInfo.toString();

        }

    }

    function errorHandler() {

        alert('Request failed. ' + args.get_message() + '\n' + args.get_stackTrace());

    }

}

sharepoint 2013 Create Custom List in javascript (CSOM)

var clientContext;
var listCreationInfo;
var web;
var list;


clientContext = SP.ClientContext.get_current();
    web = clientContext.get_web();
    listCreationInfo = new SP.ListCreationInformation();
    listCreationInfo.set_title("Use");
    listCreationInfo.set_templateType(SP.ListTemplateType.genericList);
    list = web.get_lists().add(listCreationInfo);

    clientContext.load(list);

    clientContext.executeQueryAsync(
 function () { alert("Success!") },
 function () { alert("Request failed") }
);

Application Architecture Diagram Sample 3

Application Architecture Diagram Sample 2

Application Architectural Diagram Sample 1