Prisma (for iPhone)

Even before the blockbuster success of Instagram, there was never a shortage of photo-filtering apps for iOS. To this day, the app store is chock-full of them. But every once in a while, a photo-effect app comes along that generates buzz. Using artificial intelligence technology, the app goes beyond merely filtering by letting your photos mimic the work of modernist masters like Van Gogh and Picasso. Starting Up The free app, for all its wizardry, is just a tiny 15MB download; that's because it performs its magic in the cloud (which can have its own downside, however, as I'll explain later).