Platform: Android, iOS
    
Memrise is a website which offers online learning opportunities. Whenever you need a short tutorial to learn something or let's just say prepare for a general knowledge quiz, Memrise is the way to go. 

Learning with Memrise is fun, fast and easy. Flash cards appear on the screen sequentially and the words/sentences to be learned are provided in both audio and visual mode. After you learn the words, you take small revisions in order to remember them and additionally speed tests are given in order to strengthen the memory. If you become a paid member, you can further take listening tests and review the difficult parts of your course. However, the most important parts of the courses such as gathering the integral knowledge and taking small tests are for free. Although a wide variety of courses, including pop culture and general knowledge, are available in Memrise, the most appealing part of their system is the opportunity to learn foreign languages. Memrise offers courses on a multitude of foreign languages which are easy to learn and are quite handy.

Overall, I'd say Memrise is a useful app to gather information about small things and learn foreign languages within a limited time period. If you are going on a summer trip to a non-English speaking country and you need to learn a word or two to get along, Memrise is the perfect place for you.