Bill Gates dropped out of Harvard. So did Mark Zuckerberg.

Stirred by entrepreneurial urges and a mind for developing computer software, Chris Kelsey dropped out with a 4.0 GPA during his senior year at Santa Rosa’s Maria Carrillo High School.

“I had six months left to graduate,” he said. “I purposely didn’t. I am a day-to-day person. I could die in a day. I don’t take anything for granted. I need to do things now or never. Today is the only time we have.”

When he dropped out, his parents were upset; high school and college have value for most young people. But school was uncomfortable.

“I was picked on,” Kelsey said. “In eighth grade, I would do really well on tests and get called nerd and geek. I was more socially awkward. My way of getting revenge is by becoming successful. Why spend four years in college? I know I’m going to be an entrepreneur. Why not just start now?”

He read Think and Grow Rich by Napoleon Hill, published in 1937. Kelsey thought, and determined to grow rich.

“I was obsessed with learning about business,” he said. “I was going to make my own job.” He studied body language to boost his personal effectiveness.

In December 2014, he founded Appsitude custom software company and claimed a 2015 profit of $300,000 after barely a year in business. Now he lives nomadically. Based from his parents’ Santa Rosa home and San Francisco Airbnb outposts, he jets worldwide to work with enterprises in Australia and Mexico and manage a team of code developers in the Ukraine.

Richard Branson, 65, swapped education for business when he was even younger than Kelsey. Branson dropped out of Stowe high school in England, founded Student magazine at age 16 and sold $8,000 worth of advertising into the first issue. He launched a record shop, recording studio and Virgin Music, which signed the punk-rock Sex Pistols in 1977 and the Rolling Stones in 1992. Branson’s business ride careened. Skirting financial peril in 1992, he sold Virgin Records to Thorn EMI.

His entrepreneurship bloomed anew. Virgin Group’s 200 companies employ some 50,000 people in 50 countries. Forbes estimated Branson’s worth at $5 billion. Last week, Alaska Air agreed to pay $2.6 billion for San Francisco-based Virgin America, founded by Branson in 2007. Virgin Group owned 25 percent of the airline, yielding a $650 million payday.

Will Kelsey, who turns 19 next month, fly so high? Like Branson, he embodies a sense of unlimited frontier. “I want to build an empire,” he said. “That is my goal. This company is my life.”

For starters, perhaps he’ll rethink Appsitude’s name. Branson adopted Virgin — clean, memorable. Appsitude suggests apps with attitude, Kelsey said. But customers struggle to remember and find the domain. Was it apps with aptitude — appstitude.com? Or apps with amplitude — appslitude.com? Or simply app with tude — appitude.com? Vernacular wasps buzz the business name, eager to sting.

“Yeah, people say Appstitude,” Kelsey said. “Maybe we’ll change it. The main thing is the domain.”

While the name needs a tweak, Kelsey has a gift for business opportunity. He and his “creative architects” study apps for whole industries, such as the business of art galleries. “I had them figure out the pain points,” he said, interviewing owners of nearly 30 galleries in San Francisco and London. “Art galleries are a dying industry. We can do virtual-reality apps. A lot of their clients are traveling.” He envisions an app where a customer can remotely roam through the art in a gallery and zoom in and out before bidding on art.

For each app project he seeks a budget of $250,000 to $500,000. Target industries include hotels and restaurants. He’s talking with a Mexican bank for an app contract that could bring in $1.5 million, he said. “It would take care of all security compliances,” he said of the app. “You can do checking, balances, monitor payments,” and may have a budgeting function to help customers manage finances.

He’s “building a startup without spending a year wondering if it’s going to work. We test the idea before we build it,” Kelsey said. “We were able to expand very quickly because of referrals from our previous clients. There are so many development companies that are really bad. They don’t do things on time, are not responsive.” He’s creating a custom project-management tool that allows clients to bring input to the design team and track progress.

“I want it to feel good — not just that we develop your app,” he said. One of his Ukrainian developers created an app called Premium Wallpapers HD, which downloads wallpapers and background images for smartphones and tablets.

Developers in the United States charge three or four times as much as developers with comparable coding skills in the Ukraine. “I hired the best I could find in the country,” Kelsey said. Banking clients tend to want U.S. developers, who might charge $150 an hour or more, due to security concerns. “If you paid a developer $150 an hour in the Ukraine, you are talking about the best in the country,” he said.

He hires specialized developers. Some do only virtual reality; others code only for games or for iOS, Apple’s mobile operating system. Kelsey pushes developers to crank out apps in a hurry. Speed to market means a lot in the tech industry.

His goal is to avoid venture capital and remain self-funded. “When you are making revenue, you control the rules. I’m not looking for investors. Time I spend finding an investor is time I could spend finding a client,” he said.

“For hotels, we want to do beacon technology,” Kelsey said, where a smartphone’s exact location is used to interact with beacon transmitters and obtain useful information for a guest. “When the user walks to a certain part of the hotel, say the lobby,” the phone could inform the traveler that happy hour starts soon. The app would allow a guest to order room service, rather than using a land line. “It’s such an antiquated thing,” Kelsey said.

To build an app for a chain such as Holiday Inn would be “tens of millions of dollars,” Kelsey said. Last year’s revenue reached $500,000. “That $300,000 profit was for myself,” he said. To amp up business and find new customers, he attended tech and other events in San Francisco nearly every day. “I immediately started getting more clients,” he said.

He met Chris Kettle, a self-described tech nerd who lives and works in San Francisco, London and Sydney, Australia. Initially Kettle was a client for an Uber-like ride app for Australia. Already the app has attracted some 1,000 drivers, Kelsey said. Now Kettle, a website developer who created an app called HungryHero for restaurants to offer special deals, is Appsitude’s chief of operations. He’s talking with Domino’s Pizza’s operation in Australia to create a custom ordering app.

In February “we signed $430,000 of contracts,” he said, “completely unexpected. I want this to be a multimillion-dollar company by the end of the year. I’m beginning to see how far it can go. When I first started, I thought I could make $2,000 or $3,000 a month. I had $100,000 worth of contracts in the first three months.”

He has 35 workers sprawled around the globe. “In the U.S., we are totally virtual,” he said. “In Australia as well. I think we will always stay virtual,” and likely Hong Kong. But he is setting up an office in Mexico, and one already is open in the Ukraine, where several developers work.

“It’s almost a franchise, the way we’re working,” Kelsey said. “The guy starting to run Appsitude Mexico is paying for office space. We get a percentage of profits. He gets the brand” and access to a development team. “People want to see a local face,” a company representative who knows the local language and culture.

Kelsey knows HTML and CSS for websites, but his coding skills are modest. He’s overseeing an app under development for custom homebuilding “for an architect who built Steve Jobs’ house,” Kelsey said, “Robert Redford — people like that. He wanted to show his clients the progress of a house being built.” Clients can write comments on photos of work-in-progress, an interactive online space. He aims to make the architect’s clients feel special over a building period that can last five years on houses worth $30 million and up.

The galloping enterprise is taking him for a ride. “It’s an adventure,” Kelsey said. “Wherever I’m going, it’s because there’s something good happening.”