Of all the art-driven iPhone apps—and there are many, including Brushes, the medium for newyorker.com’s Finger Painting series—few are as engrossing as the new one from MOMA. Browse the museum’s collections by floor, exhibition, and decade (including works not currently on view); audio commentary is available for select images, and doubles as an audio tour inside the museum. The app also features a glossary of art terms, an encyclopedia of modern artists, a calendar of upcoming events, and a feature called MOMA Snaps, which lets you take a picture during your visit and convert it into a postcard.