var updateWebPartTitle= function (PageUrl, SPWebPartID, generatedFile) {
        var clientContext = new SP.ClientContext(hostContextWebUrl);
    var factory = new SP.ProxyWebRequestExecutorFactory(_spPageContextInfo.webAbsoluteUrl);
    clientContext.set_webRequestExecutorFactory(factory);
    var clientContextSite = new SP.AppContextSite(clientContext, hostContextWebUrl);

    var oFile = clientContextSite.get_web().getFileByServerRelativeUrl(PageUrl);

    var limitedWebPartManager = oFile.getLimitedWebPartManager(SP.WebParts.PersonalizationScope.shared);
    var webPart = limitedWebPartManager.get_webParts().getById(SPWebPartID);
    clientContext.load(webPart);
    webPart.get_webPart().get_properties().set_item("Title", "Test");
    webPart.saveWebPartChanges();

    clientContext.executeQueryAsync(Function.createDelegate(this, function () {
        alert("done");
    }), Function.createDelegate(this, function (sender, args) {
        alert("error");
    }));
};