Famous First Websites - Discover what popular startup websites looked like at launch
Social Champ - Social Champ - The Efficient Social Media Management Tool and Scheduler
Waybackpack - Download the entire Wayback Machine archive for a given URL
Social Aider - Social Aider is an affordable, user-friendly social media management tool that helps businesses to enhance their marketing campaigns.
Youtube++ - extension to show publishing date of related youtube videos.
Social Insider - Get an inside view of your competitors' Facebook activity