Done has earned Aloha status.
As an Aloha app, Done won’t count against your system limits for apps, tabs and objects – regardless of your Salesforce.com edition.
You can install Done in Professional, Enterprise, and Unlimited editions of Salesforce.
Done even works with just a Chatter Plus license. So everyone in your company can use your Chatter social network and now, using Done, they can collaborate on Tasks.
Learn more about Done here.