What is "ghostery"

Ghostery is a proprietary freeware privacy and security-related browser extension and mobile application for Mozilla Firefox, Google Chrome, Microsoft Internet Explorer, Opera, Apple Safari, iOS, Android and Firefox Mobile, owned by Ghostery, Inc. (formerly Evidon). It enables its users to easily detect and control javascript code (commonly known as "Tags" or "Trackers") that are embedded in a web page, invisible to the user, allowing collection of the user's browsing habits via placing of HTTP cookies and other types of tracking such as canvas fingerprinting. Additionally, Ghostery’s privacy team creates profiles of page elements and companies for educational purposes.