Wonderopolis is a free app that provides you with a Wonder of the Day. This wonder begins with a "Did You Know" section which contains an explanation of the inquiry. This is great non-fiction reading source for students. For instance, generic products began appearing on shelves as white boxes with black lettering.
The Wonder Words section provides a list of vocabulary words key to the topic. Some words in the generic wonder word list include brand, product, aisle, staples, generic, and prescription.
Wonderopolis is a great, clean app providing students with interesting topics to read. If you want to investigate further, please check out the Wonderopolis.org website, where there are videos and more that correspond to this resource.