In Magento 1.7, you could only add comments to orders in backend. So we developed this extension for our customer.
After installation, it will add comment fields to both default checkout methods. Customers could still post comments after the order created by another comment form added in viewing orders. All the comments will be saved into original order history feature, you could reply it in backend directly. It won’t break any existed processes.
# Add a comment form in the final step of onepage checkout
# Add a comment form in the final step of multishipping checkout
# Add a comment form in viewing the order