The Note Reviewer plugin enhances knowledge retention by enabling users to review and manage notes based on tags. Once activated, the plugin adds an icon to the Obsidian sidebar, allowing you to easily access and review notes. Notes can be filtered and grouped by specific tags, which are detected when included within the first 10 lines of the note. A dashboard interface provides a filter dropdown for organizing notes by tags, and users can mark notes as reviewed using a checkbox, streamlining the review process for improved learning and organization.