code: public List<File> getOnApp(int appId, Integer limit, Integer offset) {
  		WebResource resource = getResourceFactory().getApiResource(
  				"/file/app/" + appId + "/");
  		if (limit != null) {
  			resource = resource.queryParam("limit", limit.toString());
  		}
  		if (offset != null) {
  			resource = resource.queryParam("offset", offset.toString());
  		}
  
  		return resource.get(new GenericType<List<File>>() {
  		});
  	}
docs: Returns all the files related to the items in the application. This
  includes files both on the item itself and in comments on the item.
  
  @param limit
  The maximum number of files to be returned. Defaults to 50 and
  cannot be higher than 100.
  @param offset
  The offset to use when returning files to be used for
  pagination. Defaults to 0 (no offset).