When we take a photo, with any camera, a shutter (as if it were the ?eye? of the camera) opens and closes for a certain period (usually a fraction of a second) in order to capture the light that will compose the image. The longer the shutter stays open, the more light it captures and it can also generate cool effects like this, this or this, as well as light games.
The app proposal PABLO., for iPhone, allow that kind of thing.
What the app allows users of iPhones to take simulated long exposure photos, of course, seals mainly in generating ?light paintings?. To do this, you need to position the fixed device somewhere, release the shutter and use some light source (such as a flashlight or even a cell phone screen) to "draw" in the air.
Check out the promotional video:
PABLO. it can generate beautiful images, depending on your creativity; then just share them via Facebook, Twitter and / or Instagram. And the best: it is free on the App Store. ?