Along with the Common Core, many state standards ask that educators incorporate multimodal resources into their lesson plans. As time goes on, more and more quality apps are available that meet that requirement. Here are a few digital resources to consider for your nonfiction science collection.   Cells (Kids Discover; $3.99; Gr 5-9) by Sean Price offers students an overview of animal, plant, and human cellular life. On opening the app, viewers can choose from 11 sections or scroll screen by screen through chapters that present both text and colorful illustrations under such headings as “The Stuff of Life,” “DNA Unraveled,” and “What Cells Do.” “Zooming In” offers a cut-away diagram with 10 clearly marked parts and functions of the cell from the nucleus to the role of the mitochondrion. When tapped, the corresponding part or parts of the cell light up (while the rest darkens), allowing students to see exactly what they look like or where they take place. “Incredible Journey" features a short, narrated video clip that takes viewers into the blood stream, zooming past red blood cells, and into the center of a single white blood cell to view chromosomes. “Engineering in a Better World?” mentions gene therapy, stem cells, genetic testing research, and  the “thorny issues” raised by genetic engineering. Music clips, animation, and interactive screens (such as a time line covering the years 1590 to 1997), are some of the additional enhancements found in the app. A maze, a simple jigsaw puzzle, and a five-question quiz are also available, but once they are tried it’s unlikely users will revisit them. There is no glossary or list of key facts. The last section contains short lists of print and web resources with live links (to Amazon, in the case of the books). Two of the four recommended books may be best suited to a slightly younger audience. Cells is also available in a Spanish language edition. —Elizabeth Kahn, Patrick F. Taylor Science & Technology Academy, Avondale, LA Kids Discover has produced a number of high quality nonfiction offerings for iOS devices and Matter ($3.99; Gr 5-8) is another. The text introduces readers to the following concepts: atoms, elements, states of matter, mixtures, and physical changes versus chemical changes, as well as real-world examples of these states and their properties. The writing is clear and precise and well suited to those new to the subject. Because the app is both comprehensive and illustrative, it could easily serve as an interactive stand-in for texts of a more static nature. The bright, sharp visuals are stunning; each page is pleasingly arranged with an appropriate balance of information and illustration. Animations, sound effects, and short video clips are incorporated throughout demonstrating, for example, how a steam engine works and what happens when a piece of dry ice (solid carbon dioxide) is dropped into a glass of water. Accompanying the text is a vocabulary matching activity and a brief five-question quiz. Interactive activities include a step-by-step experiment guide and practice problems for calculating volume. Between the lucid writing and the beautiful visuals, this app will have many classroom applications. The brief, how-to section that appears when the title is first opened serves as a tutorial on how to use the app. A worthwhile addition to nonfiction collections.— Lindsay Cesari, Baldwinsville School District, NY   Three tabs, "solid," 'liguid" and "gas," lead viewers to paragraph-length definitions and descriptions of each of the States of Matter  (Braahmam Net Solutions Pvt. Ltd.; Gr 5-8) in this free app. In addition, a list of properties is provided for each state, as well as an animated "demonstration" of its particle activity and forces. Finally, a quiz consisting of 10 simple true-and-false and mulitiple-choice questions is provided. The language of the text is awkward at times, suggesting a translation. Viewers can opt to read it or listen to the narration. While neither deep nor particularly exciting in presentation, the app may offer students an opportunity to test or review what they know about the topic.—Daryl Grabarek, School Library Journal