The Chrome Web Store is Google's online store for extensions and themes for the Chrome browser. An extension is a small program, packaged as a ZIP file with a manifest (a file that declares its name, version and permissions), that adds features to web pages or to the browser; a theme changes how Chrome looks. Users install items at no charge.
A developer registers once in the Chrome Developer Dashboard, agrees to the developer agreement and policies, and pays a one-time registration fee. The developer then uploads the ZIP file and fills in the store listing, the privacy fields (the extension's single purpose and how it handles user data) and the distribution settings, such as a paid item or not and the countries that list it. Every submission, new item or update, is reviewed by manual and automated systems against the developer program policies; most reviews end within a few days. A new publisher can have at most two published extensions at first. An API can upload and publish new versions.
Browsing and installing are free. The pages read do not state the amount of the registration fee.