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.
This extension only cost you 6.99 USD. If you are coming from Taiwan, we could provide official invoice to you. The price here is tax excluded.
You could purchase this extension by making a payment in Paypal. If you need other payment methods, please contact us first.