A little more than six months ago, Yan-David Erlich was sitting in a restaurant when he noticed a waiter bring a black-and-white coloring pad plus some crayons to the children sitting at the next table.

“I started wondering what the online equivalent of that was,” he recalls. “And I realized that while it’s hard to draw with a mouse, it’s easy when you use your fingers on a touchscreen.”

That realization led to Colorized, an iPhone app that facilitates “social sketching.”

With the app, you snap a photo, and then use a suite of virtual tools – a pencil, spray can, felt tip pen, eraser, a camera, stamps (including a mustache, a Panda, and a monocle) -- to enhance or alter it any way you wish.

Then, a “remix” function allows you and your friends (or the entire Colorized community) to iterate on it endlessly.

By combining photography with doodling on the touchscreen, Colorized is essentially enabling users to create a new form of art.

The camera has two filters, one of which strips the color out of a photograph, leaving the black and white outline that is the digital equivalent of that coloring pad in the restaurant, and a second filter that does a little of the coloring in for you.

When you are satisfied with a piece, you can publish it on Colorized, where it can be shared just with friends or the community at large, and on social media channels as well. Early users seem to enjoy remixing each other’s work; setting off what Erlich calls a “conversation in pictures.” People can “like” and add text comments to the pictures.

The pictures posted on the app flow into a Facebook-like central feed.

“We think at the start, we are providing a set of fairly simplistic tools,” says Erlich. “Even so, the quality has surprised us. Some of it is amazing art. It shows that if you give artistic people tools, they will create beautiful stuff.”

Colorized is a product from Happiness Engines, a startup that “works to change the way people interact with their mobile device and personal services, in a manner that's completely fluid and intuitive.”