Generic starting point to give a (more or less) subtle visual cue a tableview row is being selected.

tableview & collectionview cell "pressed down" effect

/// table view


-(void) tableView:(UITableView *)tableView didHighlightRowAtIndexPath:(NSIndexPath *)indexPath
{
    UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
    cell.contentView.alpha = 0.7;
    [UIView animateWithDuration:0.15
                          delay:0.0
                        options:UIViewAnimationOptionCurveEaseInOut
                     animations:^{
                         // "pressed down" effect. move the cell 2% to the left and reduce its size by 3%.
                         CGAffineTransform transform = CGAffineTransformMakeTranslation(-CGRectGetWidth(cell.contentView.frame) * 0.02, 0);
                         transform = CGAffineTransformScale(transform, 0.97, 0.97);
                         cell.contentView.transform = transform;
                     } 
                    completion:nil];
}

-(void) tableView:(UITableView *)tableView didUnhighlightRowAtIndexPath:(NSIndexPath *)indexPath
{
    UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
    cell.contentView.alpha = 1.0;
    [UIView animateWithDuration:0.1
                          delay:0.0
                        options:UIViewAnimationOptionCurveEaseInOut
                     animations:^{
                         cell.contentView.transform = CGAffineTransformIdentity;
                     }
                     completion:nil];

}


/// collection view

-(void) collectionView:(UICollectionView *)collectionView didHighlightItemAtIndexPath:(NSIndexPath *)indexPath
{
    UICollectionViewCell *cell = [collectionView cellForItemAtIndexPath:indexPath];
    
    cell.alpha = 0.7;
    [UIView animateWithDuration:0.15
                          delay:0.0
                        options:UIViewAnimationOptionCurveEaseInOut
                     animations:^{
                         // "pressed down" effect. move the cell 2% to the left and reduce its size by 3%.
                         CGAffineTransform transform = CGAffineTransformMakeScale(0.95, 0.95);
                         cell.transform = transform;
                     }
                     completion:nil];
}

-(void) collectionView:(UICollectionView *)collectionView didUnhighlightItemAtIndexPath:(NSIndexPath *)indexPath
{
    UICollectionViewCell *cell = [collectionView cellForItemAtIndexPath:indexPath];
    cell.alpha = 1.0;
    [UIView animateWithDuration:0.1
                          delay:0.0
                        options:UIViewAnimationOptionCurveEaseInOut
                     animations:^{
                         cell.transform = CGAffineTransformIdentity;
                     }
                     completion:nil];
}