If you don't have this on your phone I feel sorry for you Let's put aside for a second that this app  in a few clicks  can show you a small but good enough summary of almost any sort of knowledge that the human species has collected through the ages and just admire the offline mode and the ability to switch the language of the page. Seriously if you don't have this app and use it from time to time I'm judging you.
October 12 2016