Inspired by the 2011 Occupy Wall Street movement, Vladimir Tenev and Baiju Bhatt founded a no-fee trading app called Robinhood. They wanted to 'democratize access to the financial markets.'

Robinhood launched in December as an iPhone and Apple Watch app. It lets people - primarily first-time investors - buy and sell stocks without being charged commission fees, which usually run between $7 and $10.

Unlike regular trading, Robinhood is mobile-first. This cuts out the cost of paying human traders.

On Thursday, Robinhood announced the company had raised a $50 million round led by NEA. Vaizra Investments joined the round with existing investors Index Ventures, Social Leverage, and Ribbit Capital, bringing Robinhood's total funding to date to $66 million. Previous investors in the company include Snoop Dogg and Marc Andreessen.

The company will use the new funding to grow its team. The founders hope to double Robinhood's Palo Alto headcount of 30 employees by the end of the year. In addition, they'll be launching an Android app later in 2015.

Robinhood will also begin expanding to international markets, beginning with Australia. Australians will be able to access US listed stocks and ETFs. A representative for Robinhood says the company is seeing 'huge demand' from the country already.

Robinhood users don't pay traditional brokerage commission fees, which Robinhood's founders see as prohibitive to new investors. The app's users also don't have to put down a minimum deposit.

Robinhood follows a freemium model - it allows customers to buy and sell US stocks and ETFs, customize watch lists, place market orders, and track data in real time. Those looking for premium services like margin lending, however, will have to pay a fee.

The company says that since December, it has seen over $500 million transacted through the Robinhood platform. It also says it has had 'hundreds of thousands' of customers since its launch five months ago. One-fourth of Robinhood customers are first-time investors, and the average age of a Robinhood customer is 26.