These two 24-year-old entrepreneurs are the founders of app development company Appster.

Since 2011, they’ve made apps for clients including Bluedot and radio hosts Hamish and Andy.

Today, Appster has offices in Melbourne, India and San Francisco, and employs more than 200 development staff.

Humphrey’s advice for budding entrepreneurs is to not listen to people who say that something’s impossible and to create a compelling vision that inspires your employees.

“The secret is that the most talented people want to work for a company that is trying to do great things,” Humphrey says.

“They themselves are ambitious. People want a reason to get out of bed in the morning. They want something ambitious [and] to come on a journey with you.”