I noticed that every time my GMGridView needs to refresh, it re-creates all cells, which takes a long time. 
Is there some way to assign a reuse identifier to GMGridViewCell or somehow ensure they are reusable?
Here's the code that I have that re-creates all visible views each time.
  - (GMGridViewCell *)GMGridView:(GMGridView *)gridView cellForItemAtIndex:(NSInteger)index
    {
        NSLog(@"Creating view indx %d", index);
        CGSize size = [self sizeForItemsInGMGridView:gridView];
        GMGridViewCell *cell = [gridView dequeueReusableCell];
        if (!cell) 
        {
            cell = [[GMGridViewCell alloc] init];
            cell.deleteButtonIcon = [UIImage imageNamed:@"close_x.png"];
            cell.deleteButtonOffset = CGPointMake(30, -20);
            UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 57, 57)];
            cell.userData = [[IconFile allObjects] objectAtIndex:index];
            UIImageView* imageView = [[UIImageView alloc] initWithFrame:view.frame];
            NSIndexPath* indexPath = [NSIndexPath indexPathForRow:index inSection:0];
            IconFile* iconFile_ = [self.fetchedResultsController objectAtIndexPath:indexPath];
    //        imageView.image = [UIImage imageNamed:@"retina_114x114_1.png"];
            imageView.image = [UIImage imageWithData:iconFile_.image114];
            [view addSubview:imageView];
            imageView.center = view.center;
            imageView.layer.masksToBounds = YES;
            imageView.layer.cornerRadius = 9;
            view.backgroundColor = [UIColor clearColor];
    //        view.layer.masksToBounds = YES;
    //        view.layer.cornerRadius = 9;
            view.layer.shadowColor = [UIColor grayColor].CGColor;
            view.layer.shadowOffset = CGSizeMake(5, 5);
            view.layer.shadowPath = [UIBezierPath bezierPathWithRect:view.bounds].CGPath;
            view.layer.shadowRadius = 9;
            ShadowLabel *label = [[ShadowLabel alloc] initWithFrame:CGRectMake(0,0,72,21)];
            label.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
    //        label.text = (NSString *)[_data objectAtIndex:index];
            label.text = iconFile.springBoardName;
            label.layer.shadowPath = [UIBezierPath bezierPathWithRect:label.bounds].CGPath;
            label.layer.shadowRadius = 9;        
            label.textAlignment = UITextAlignmentCenter;
            label.backgroundColor = [UIColor clearColor];
            label.textColor = [UIColor whiteColor];
            label.font = [UIFont boldSystemFontOfSize:11];
            [view addSubview:label];
            label.center = CGPointMake(size.width/2, 60);
            cell.contentView = view;
        }else{
    //        [[cell.contentView subviews] makeObjectsPerformSelector:@selector(removeFromSuperview)];
    //        
    //        UILabel *label = [[UILabel alloc] initWithFrame:cell.contentView.bounds];
    //        label.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
    //        label.text = (NSString *)[_data objectAtIndex:index];
    //        label.textAlignment = UITextAlignmentCenter;
    //        label.backgroundColor = [UIColor clearColor];
    //        label.textColor = [UIColor blackColor];
    //        label.font = [UIFont boldSystemFontOfSize:20];
    //        [cell.contentView addSubview:label];
        }
        return cell;
    }
				
                        
Might be this is too late to answer this Question but I have an answer for this.
For Reusing GMGridCell, you need to assign reuse identifier after you alloc your cell May be like this