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: TiddlyWiki is a free and open source personal wiki application that runs entirely in a web browser. It allows users to create richly formatted notebooks that contain notes, to-do lists, images, and links for organizing and sharing information.
Type: software
Pricing: Open Source