San Francisco: Many new startups are now focused on developing application and games for iPhones as they feel it is a platform that can make their company successful as well as earn good revenue.

"This is our dot-com boom," said Samir Shah, 26 years old, a Co-Founder of Mountain View-based Snapture Labs LLC, which makes a $1.99 camera app that has been one of the top-ranked photography apps since September. Shah and two other Snapture co-founders work on their iPhone business in their free time from one of their apartments, but said they hope to eventually turn it into a full-time business, according to the Wall Street Journal.

Apple has sold more than 30 million iPhones and 20 million iPod touch and has more than 100,000 apps on its App Store. Through app store people can download games, entertainment and utility applications for free or less than one dollar.

Developers get 70 percent of any revenue they make from app sales, with the remaining 30 percent going to Apple. That is a better proposition than app development for other mobile phones has been in the past. Rivals have been forced to offer similar revenue-share models now. As a result, many Silicon Valley techies have been lured to the iPhone app start-up scene. According to Mobclix, which operates the iPhone's largest ad-exchange network - a marketplace to connect advertisers and app developers - 41 percent of its 4,000 app developers are in Northern California. The region with the second-largest number of app developers is New York-New Jersey, with 14 percent.

"A large concentration of people who are doing (iPhone apps) are Internet entrepreneurs...and a lot of Internet entrepreneurs are in the Valley," said Matt Murphy, who oversees the $100 million iFund, a venture-capital fund run by Kleiner Perkins Caufield & Byers that backs iPhone app developers.

Silicon Valley's universities are also coaxing the iPhone app boom along. In September 2008, Stanford University began offering an iPhone app-building course taught by Apple's engineers. It also posts the course online free. Roughly 130 students have taken the course since last fall, and more than one million people have downloaded the lectures, said Julie Zelenski, a Stanford lecturer in computer science.

Edward Marks, founder of iPhone app start-up Inedible Software LLC, is one student who took the Stanford course and then set up his company in Palo Alto in June upon graduation. The 23-year-old said he briefly considered moving to Hawaii but realized everyone he wanted to do business with was in the Bay Area. "We just realized that this was basically the center of the iPhone world," he said.

Some local techies are finding the iPhone app opportunity so attractive that they left jobs at more secure tech firms to jump into the scene. Sam Yam, 25, one of the founders of AdWhirl, a Palo Alto ad network company for iPhone apps, says he left a job at Mountain View service company Loopt in February to start the company, which helps manage ad placement in iPhone apps.