We see lots of game apps and while many will hold children's attention for a while, only a few will have them returning again and again. The five reviewed below are spot-on. Three are for the preschool through early elementary set, but Monument Valley and Petting Zoo had the adults in our office passing around the tablet.

Screen from 'Axel Scheffler's Flip Flap Farm' (Nosy Crow) Scheffler

Axel Scheffler’s Flip Flap Farm (Nosy Crow, $.99; PreS-Gr 1), a combination of verse, colorful art, and silly play, is sure to win favor with young children, and some older ones as well. The object of the game is to create animals; a swipe of the top panel of the screen allows viewers to choose the upper half of the creature and a second swipe to the lower panel, the feet. While the combinations can yield accurate pictures of barnyard denizens, the fun is in mixing the features to create a new ones. Daft blends—a shicken (half sheep, half chicken); a tabbit (half turkey, half rabbit); a moat (half mouse, half goat)—or any of the other 121 possibilities ensure tons of fun. Rhyming poems for each creature (Moat:“I am the smallest animal/you’ll find down on the farm./I hide inside my tiny hole,/and keep away from harm....”) and appropriate animal sounds will help kids identify the creatures. Children can choose to read the verses or listen to the child-read narration. There is no end per se to the app, just more combinations to be tried. A trailer is available. A spiral bound book of Flip Flap Farm (Nosy Crow, 2013) offers a similar experience on paper—minus the sound track. The latest addition to the series, Alex Scheffler's Flip Flap Safari (Nosy Crow, $.99; PreS-Gr 1), employs the same enthusiastic child narrator. The animals featured are those found in Africa, from giraffes and elephants to warthogs and zebras, combining to make such fanciful creations as wartaffes and zebants. A trailer is available, as is a book by the same title (Nosy Crow, 2014). The series focuses on producing one quality activity, fueled by the power of the user’s imagination and sense of humor.—Cindy Wall, Southington Public Library, CT

Interior screen 'Gruffalo: Games' (Magic Light/Stormcloud Games) Scheffler

Gruffalo: Games (Magic Light Pictures Ltd/Stormcloud Games Ltd., $4.99; PreS-Gr 1) is an engaging app inspired by Julia Donaldson’s The Gruffalo (Dial, 1999), illustrated by Axel Scheffler. Games consists of six interactive activities featuring characters from the popular picture book. While Mouse outwits Gruffalo in the book, in the app, children get to match wits with the creature. An easy-to-navigate menu invites players into a colorful wooded world offering a variety of games. In “3 in a Row,” the Gruffalo’s not-so-terrible claw emerges to scratch a tic-tac-toe board in the dirt, challenging children to strategize. In "Nut Catch," players must help Mouse secure nuts while he dodges falling pinecones and caterpillars and races against the clock to top his best score. “Jigsaw” requires children to complete six puzzles of increasing complexity, and for “Snap,” a card game, speedy fingers that can grab matching pairs before Gruffalo does are an asset. “Marching Bugs” and “Match Me” call problem-solving, observational skills, and nimble reactions into play as children explore patterning and engage in shape, color, letter, and number recognition. The activities, which  children will want to revisit to surpass earlier scores, are executed with taps and swipes. Background music and sound effects blend seamlessly into each game, building anticipation while remaining unobtrusive. Whether familiar with Donaldson’s story or not, kids will find Gruffalo: Games loads of fun. Available in English, French, and German.—Diane Sustin, Cuyahoga County Public Library, OH

Screen from 'Petting Zoo' (Fox and Sheep) Niemann

Simple line illustrations by famed illustrator Christoph Niemann belie Petting Zoo's (Fox and Sheep GmbH, $2.99 in iOS and Android; PreS-3) masterful presentation. The app features 21 animals, each with their own chapter of whimsical animations. The opening screen depicts a pencil drawing an image of a hat, from which a rabbit with impossibly long ears emerges. Swiping and tapping the creature stretches or squishes it and youngsters will gleefully await the next delightful animation sparked by their fingertips. Though the app is eminently intuitive, a simple, visual tutorial may be accessed from the title screen. Users have the option of turning the animated transitions off between screens, but doing so significantly limits the fun. What child wouldn’t want to see animals morph from one shape to another: the rabbit into a house from which a break-dancing dachshund emerges? Or witness a lion’s tail turn into the body of an alligator, whose mouth then fills with sharp teeth? Bold colors and black line are featured throughout, but some of the scenes feature animate objects. Occasionally the twangy guitar sound track can feel at odds with the sounds accompanying the animations, but if and when that happens, users can mitigate sensory overload by switching the music off. Since it has neither text nor narration, this app provides an excellent opportunity to get kids to talk about what’s happening on the screen. With its element of surprise, viewers never tire of in Petting Zoo's charm. A trailer is available.—Lalitha Nataraj, Escondido Public Library, CA Eds. Note: Petting Zoo is available in "English, Dutch, French, German, Italian, Japanese, Korean, Portuguese, Russian, Simplified Chinese, Spanish, and Traditional Chinese".

Screen from 'Monument Valley' (ustwo Studio Ltd.)

Lured in by the lovely, serene graphics and lulled by peaceful, intriguing music, users will find themselves unable to leave the mesmerizing Monument Valley (ustwo Studio Ltd, $3.99 for both iOS and Android; Gr 3 Up). Time loses all meaning as viewers help the tiny princess Ida climb ladders and descend stairs and follow paths that defy gravity, if not geometry, as they solve each puzzle (10 "chapters" so far with the promise of more to come). The puzzles or structures that Ida must navigate—underground, in the clouds, and at sea—call to mind the work of M. C. Escher and the properties of a Mobius strip, and invite contemplation and play. Every screen offers surprises—piers that move up and down, panels to step on, handles that reorient the entire maze. Boxes unfold from within walls and stairways shift, resembling the stair hall at Hogwarts. Pesky crows impede the girl's progress, but a bright yellow "totem" gives her a boost just when she needs it. A guru in a turban admonishes her with unhelpful advice. Marvelous details abound: Ida's footsteps pit-pat, barely audible, as she scurries up and down; murals on the walls of the mazes tie in to the mysterious underlying narrative. A sound track of muted gongs, plucked strings, and ambient chords, along with architecture full of domes and arches, give the game a vaguely Eastern atmosphere. These mind-bending puzzles are devious enough to still pose a challenge after more than one go-around, which is nice, because Monument Valley is a literally captivating place to visit.—Paula Willey, Pink Me For additional app reviews, visit our Touch and Go webpage.