Publons is a profile tool from Clarivate Analytics, which also owns Web of Science and Journal Citation Reports (which publishes the Journal Impact Factor), that allows researchers to aggregate their research activity as authors, journal editors, and peer reviewers.
It is a unique tool for demonstrating impact of peer review (among other forms of research outputs), and the platform's verified reviews are tracked by Altmetric, a data provider that tracks online attention to research.
You can also access Publons from the Web of Science (linked below). Simple click on Publons in the top navigation menu bar.