Prior to December 6, 2012, Google offered a free edition of Google Apps — also known as the legacy free edition. As of December 6, 2012, Google stopped offering the free edition to new customers.
If you have a Google Apps Free edition account (at ggappsfree.com, we can change make your domain as primary domain on this free edition account), So you can continue your service for free, without any change in service. The fact that Google discontinued the free edition for new customers has no effect on existing customers of the free service. Read more