Koober: Casual Learning, an Android app developed by Koober SAS, is a free education and reference app that offers a vast library of summarized eBooks, documentaries, conferences, and learning programs. With more than 2 million users, Koober is the number one self-improvement app that blends the best of personal development, productivity, and general knowledge. The app aims to help users reach their personal and professional goals by offering the most impactful ideas drawn from the top content sources in the form of eBooks to read or listen to in just 20 minutes. The app includes over 1,500 books, conferences, and documentaries summarized in 20 minutes or less and over 100 learning and development programs. Koober's key features include a recommendation engine, audio versions of every koob in the library, a possibility to read and listen to content offline, and tailored tips and tools delivered in "handbooks" to prompt users to put the ideas they've just learned into practice right away.