Mendeley is a free reference manager and academic social network that helps you organize your research, collaborate with others, and discover the latest research:
Zotero is a reference manager designed to store, manage, and cite bibliographic references, such as books and articles. It is also a powerful tool for collecting and organizing research information.
Official WebsiteGuide to creating profiles and finding metrics for authors, articles, journals, and institutions. These resources help identify citation metrics and alternatives to measure impact, including: