Super Forms – MailChimp Add-on
With this plugin you will be able to update your current subscribers and add new subscribers to a given listing within your MailChimp account. Not only that but you can also allow your subscribers to even update their current interests. Of course, you will need to have groups setup for the selected listing! This however is an optional feature and is not required. If you have groups setup, this Add-on will automatically retrieve the so called interests.
More download links
Link for download. User database file links.