A long-awaited boost in iPad sales may have been news this week to Apple investors, but it was no surprise to Marty McDonough, who develops apps for the company's mobile platform, iOS.
McDonough says his latest project was not only built for Apple's tablet computer, but that its very existence was inspired by the high-end iPad Pro.
"When I saw what the pencil and the iPad Pro could do, I said, 'That's cool, I need to build something'" that takes advantage of the product's digital stylus, McDonough, 37, told CNBC. "It was definitely the inspiration."
The resulting program, called ShadowDraw, teaches users how to draw by mimicking -- step-by-step -- the style and hand strokes of famous artists.
"It's like karaoke for drawing," McDonough says of the app, which will be available later this year.
One of his previous apps, an automated language tool called Odyssey Translator, has been downloaded more than 3.5 million times from the AppStore since he created it in 2009.
McDonough's drive to create another iOS-based app shows how Apple's ability to innovate has inspired its army of outside developers to keep making compelling software for its products.
It also helps explain iPad resurgence in the second quarter -- unit sales were up 15 percent from a year earlier to 11.4 million units. It was the first year-over-year sales rise for the product in three years, and part of better-than-expected quarterly results that helped drive Apple shares to a record high.