I followed the Sharepoint Hosted App demo with a List Instance in it and to get the list items it used:
varurl = appwebUrl +"/_api/SP.AppContextSite(@target)/web/lists/getbytitle('TempList')/items?@target='"+ hostwebUrl + "'";
Problem is I can get this working for existing lists, but not for The List Instance created in my App Project. Do I need a GUID instead or is it a case that the list is not being created? Error is URL Not Found.