Description: Duolingo is a free language-learning platform that offers over 100 total courses across more than 30 languages. The bite-sized lessons make it easy to learn a new language through fun, quick activities on your phone, tablet, or computer.
Type: software
Pricing: Freemium
Description: Wikidata is a free and open knowledge base that can be read and edited by both humans and machines. It acts as central storage for the structured data of its Wikimedia sister projects including Wikipedia, Wikivoyage, Wiktionary, Wikisource, and others.
Type: software
Pricing: Free