Here are some of the available add-ons to buy or download:
Feed Parser is a plugin for ExpressionEngine 2 to fetch and read XML-based feeds and API results and display the contents in your templates.
The Selected Items module allows you to select and order the content how you want to
The Members module enables you to easily find and remove Spam member accounts from your EE2 site.
The Followers module allows you to create friend-like relationships between site members.
FeedGrab is a plugin for Expression Engine to provide it with the ability to import data from 3rd party web feeds (RSS or ATOM), such as flickr or delicious.
The XMLGrab plugin allows you to insert the contents of an XML file (or feed, or API response) into Expression Engine weblogs.