Utilizando NSFetchedResultsController

gistfile1.m

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    UITableViewCell *cell = ...;
    TGRTweet *tweet = [self.fetchedResultsController objectAtIndexPath:indexPath];
    
    // Configuramos la celda usando los atributos del tweet
    // ...
    
    return cell;
}