The document discusses the best Moodle extensions that a teacher might not be aware of, including extensions that allow for automatic tables of contents, translation of content into multiple languages, revealing hidden text as students read, using maps, integrating Twitter searches, tracking student progress, allowing student self-grouping, creating custom surveys, collapsing sections to avoid long pages, and marking up PDF assignments without leaving the browser. It provides descriptions and examples of 10 extensions, ranking them from 10 to 1 in order of suggested usefulness.