I know it might shock you digital children of the world, but you don't need an app to make your pictures soft and fuzzy with leaky strands of light crisscrossing the image.
Before the dawn of the iPhone, there was this thing called film, and there were these special sorts of cameras that would automatically render these effects on your pictures. Lomography has brought back the Holga (first invented in Hong Kong during the '80s) for analog photography fans to play with. Most of the Holga series shoots with medium-format films and produces dreamy, colour-washed images that would make Instagrammers instantly jealous. A Holga starter kit comes with the camera ($75), a plastic 60/8 optical lens, built-in colour wheel (with different colour gels) and a book featuring Holga photography.
If you want to get even crazier, look at Lomography's pinhole cameras and the Diana series.