A clever physics puzzler developed by Chillingo, “Contre Jour” marries gorgeous art, a compelling soundtrack and challenging gameplay. It’s all about getting an odd-looking eyeball known as Petit from point A to point B. Along the way, he must collect orbs of light. The app’s name derives from French for “against daylight,” which is reflected in the game’s landscape of haunting silhouettes. As you manipulate this world with your fingers—using tentacles, blowers and slingshots—Petit warbles with delight and grumbles when things don’t go as planned. The likable hero and engaging storyline add up to a strange gem of an app that you must try.