i added client web part to host site, it's the out of the box sharepoint hosted app that comes by default with visual studio 2013. when adding the app part to my web page, it gives me (working on it..), but no updates, it should display hello and user name as it does in the app. any idea?
This is a normal behavior when you try to show a page from an App in SharePoint host site, in every page in your App make sure you add:
<WebPartPages:AllowFraming ID="AllowFraming" runat="server" />
Basically SharePoint pages send specific header in its response which prevents it from being viewed in iframe.