“In Stockholm, Sweden, researchers have found a way to create usable energy from the excess body heat generated by the quarter million commuters who pass through the city’s train station every day.” That's just one fact that I learned from Energy, reviewed below by Elizabeth Kahn. Consider incorporating this interactive production into your collection to support units on the environment or to highlight Earth Day (April 22). For other apps on the topic, visit an earlier published piece, Apps for Earth Day. Following the same format as the other apps in the Kids Discover series, this new production cover the various forms of Energy ($3.99; Gr 4-8) that humans harness as well as the energy that they and plants produce. Viewers can access information  via a scrollable, thematic table of contents on the opening screen or through a visual index of the 11 chapters. Once inside the app, they can swipe their way through it page-by-page, hop about using the scrubber bar on the bottom of the screen, or tap the home icon to return to the index.

Screen from 'Energy' (Kids Discover)

Eight of the 11 chapters are comprised of several pages of information on the types and use of energy (“Light and Heat”; The Boiling Point,” etc.), while others have a more ecological focus (“Energy Yesterday and Today,” “Save Your Energy”). Each page or screen begins with a video clip (of wind turbines, a waterfall, a geyser, etc.) or a colorful photo or labeled diagram, and includes a fact or two or a paragraph of text, or poses a question. Visual cues or instructions indicate where to find interactive elements and additional screens of information. A few sidebars highlight figures, and there are mentions of events such as the bike-sharing program that began in New York City in  2013. The text includes some definitions (geothermal, etc) and a few simple demonstrations (fission vs fusion, etc.), but there is no glossary or list of key facts. The last three sections offer activities, a quiz, and a list of resources. The  first two will be enjoyed for their simplicity, but readers are unlikely to choose to revisit them (the quiz contains only five questions). The "Resources" section offers five Internet and six print resources. The websites can be accessed from the app, while the book links lead to Amazon pages. All in all, solid information in an engaging presentation.—Elizabeth Kahn, Patrick F. Taylor Science & Technology Academy, Avondale, LA For additional app reviews, visit the Touch and Go webpage.