One of the most fun features found on many analog cameras was the option to expose a single frame of film multiple times, capturing separate images overtop each other to create an eerie, fantastic, or just plain cool effect. The practice hasn't been entirely lost in the digital age, but now the app Dubble, which launches today for iOS, is trying to put a new spin on it: rather than overlaying two of your own photos, it mashes your photo up with a completely random one taken by someone else.

Like multiple exposures have always been, the results can often be a pleasant surprise, seeing how features align and ghostly landscapes overlap. There can be some frustration when a great photo you've taken ends up on top of a bland picture of someone else's dog or a portrait of Molly Ringwald that someone's been spamming the network with. But when two great images match up, the serendipity can be quite charming.

Photos come back looking like they've gone through a filter too — and in fact, it should make complete sense to learn that the entire idea behind the app came from a photographer who used to work for Lomography, the maker of cameras often known for their saturated colors, vignetted borders, and multiple exposures. Dubble itself isn't perfect just yet though: it sometimes uploads your photo twice, it's a little cluttered and confusing to move around, and it takes a minute or so before it returns your photo as a double exposure. But if you don't take your uploads too seriously, the app can impress you when everything aligns just right.