GOODNIGHT, GOODNIGHT, CONSTRUCTION SITE

A jaunty tour through an urban construction site extends the best-selling picture book's audience to young app users.

The scene is a building site. The characters are Crane Truck, Cement Mixer, Bulldozer, Excavator and Dump Truck (all proper names, by the way). They toil all day, and via the touch screen, each element on the screen is identified: the vehicles, the construction site, the building under construction. The identifying words range from simple—puddle, rock—to the more challenging: spigot, hook block, heap, concrete. After the day’s work is done, the vehicles take a well-earned rest, set to couplets: “Turn off your engines, stop your tracks, / Relax your wheels, your stacks, and backs.” The Crane Truck holds a teddy in its bumper, the Cement Truck has a security blanket, and the rest of the vehicles are tucked into the dirt. It’s a pretty cozy scene, drawn with what feels like the side edge of a colored-pencil’s lead and animated with admirable restraint. With its surprising but manageable complexity, identifiable characters and pleasingly chaotic construction site, this is one of those deceiving apps that will exceed expectations, delivering the entertainment goods each time. Adding to the merriment is the plinking piano and xylophonelike soundtrack.

Watching a bunch of trucks at work. Life doesn’t get much better. And these guys talk to you.