Touch Press, the creators of The Sonnets by William Shakespeare and Beethoven's 9th Symphony have done it again. Read Gretchen Kolderup's review of their latest production below. “Math is Beautiful,” so the introduction to Touch Press's latest app claims–and Incredible Numbers (Touch Press/Profile Books, $9.99 launch price; Gr 7 Up) delivers an elegant proof. Created by professor and pop-science writer Ian Stewart, Wolfram Research co-founder Theodore Gray, and Mathematica expert Phil Ramsden, the app guides users in a visual exploration of mathematical concepts such as pi, polygons, primes, factorials, and infinity as well as applications in cryptography, nature, and music. The content serves a range of audiences: the text accompanying each section is fairly deep and assumes a basic familiarity with fundamentals of algebra and geometry as well as series, trigonometric functions, and irrational numbers, but selected in-text dictionary functionality (and brief biographies of famous mathematicians) may help. The visual and (70-plus) interactive elements are more welcoming to those who enjoy mathematical exploration but may not yet have the technical vocabulary or exposure to how concepts connect, while the nature and music sections are especially friendly to novices, and a collection of puzzles (answers included) round out the more enticing end of the spectrum for casual users. Touch Press is known for its deep, immersive productions such as The Elements: A Visual Exploration, and while Numbers is perhaps not as rich an experience, its visuals are appealing, clean and colorful in the iOS 7 style. The interactive elements are occasionally a bit perfunctory, such as requiring a simple swipe or scroll to draw out a pattern, but being able to see data and patterns grow at one’s own pace or multiple times will help users grasp concepts. The code-breaking and music sections also allow users to play around, independently investigating the effect of different input. While the app may not convert the truly math-averse, it will take enthusiasts deeper into the sanctum sanctorum of mathematical beauty.–Gretchen Kolderup, New York Public Library, NY For additional app reviews, visit the Touch and Go webpage.