Stephane Kardos, a Los Angeles-based artist who is also an art director for the Walt Disney Co. (also the parent company of ABC News), was one of the first to use the program and has posted about 45 images of the Los Angeles area online.
Colombo said Kardos' sunset paintings partly inspired him to experiment with iPhone art.
Kardos's sketches are also done on site and take about 5 to 10 minutes to complete.
"The sunsets can be done even faster as the light is changing very quickly," he wrote.
Patricio Villarroel, a Paris-based artist, was also one of the first to download the Brushes application. Since 1996, he said he's been creating virtual paintings on his Mac. He migrated to the iPhone 2 weeks after Sprang launched Brushes.
But though professional artists have gravitated to the program, Colombo insists that iPhone art is for everyone.
"People should have fun," said Colombo. "It's good to do something that you can record your moments, create your own images. I still recommend people to play. I don't think play enough with pens and pencils and colors as much as they should."
ABC News' Wonbo Woo contributed to this report.