THE CRANKAMACALLIT

A brawny antidote to the fairy-tale adaptations and cutesy cartoon-character apps that overstuff the App Store, this ear-catchingly titled story is all about power tools and building.

Promising to help readers build a Crankamacallit, "With buttons and levers and yes, of course—CRANKS!", the app fills its pages with red and green buttons, a toolbox full of building instruments and, later, an orchestra pit built into what looks like a birthday-party-balloon–powered zeppelin. There are blueprints, a silly notepad filled with illustrated engineering notes and the occasional flight of fancy. (Literally, in one case: an inspirational flying goose.) The visual style is a curious mix of near-photorealistic artwork and polished computer animation. Near the end, running a finger along the screen generates a thrilling rotating view of the finished flying vehicle. The sound effects and narration are energetic and satisfying. But many of the elements, including some of the buttons and schematics, are difficult to interact with because the app reads many taps as page turns. It's far too sensitive, and unnecessary to boot, given the page-turning arrows on the bottom corners of each page. In fact, navigation in general is overdone and fussy given the subject matter. There are four different ways to navigate, and that's probably two too many for an app with only 20 pages total.

Nevertheless, it's got a formidable array of virtual mechanics that'll wow any kid who's starting to look beyond LEGOs for bigger building blocks.