Is it somehow possible to use the XsltListViewWebPart in the SharePoint-Hosted App to view and manipulate a List of the Hostweb?
<WebPartPages:WebPartZone runat="server" FrameType="TitleBarOnly" ID="full" Title="loc:full">
<WebPartPages:XsltListViewWebPart runat="server"
ListUrl="Lists/Listname" <--- Relative URL! Only AppWeb? Or also HostWeb?
IsIncluded="True"
JsLink="clientTemplate.js"
NoDefaultStyle="TRUE"
PageType="PAGE_NORMALVIEW"
Default="False"
ViewContentTypeId="0x">
</WebPartPages:XsltListViewWebPart>
</WebPartPages:WebPartZone>