Quixey, one of the several start-ups trying to crack mobile app search, is proving just how hard it is to turn that vision into a business.

Less than a year and a half after raising $60 million (at a valuation of about $600 million) from investors including Alibaba and SoftBank, Quixey is turning to the debt market for another $30 million, according to a regulatory filing on Thursday. It's the first major move under new CEO Mark Lazar, who replaced founder Tomer Kagan in April.

Struggling start-ups often raise debt to avoid having to sell equity at a price below the previous round, a move that's become more prevalent since the venture capital market started slowing late last year. The company said the money was provided by existing investors and, according to the filing, provides the "right to acquire other securities upon conversion of the debt."

Quixey, of course, put a positive spin on the financing. The company has been focusing on what it calls "deep mobile search," helping consumers find information inside of apps, where traditional web search doesn't work.

"Our innovative technology enables users to find actions inside apps and take them directly to the answer they are looking for," said Kagan, who is still with the company, in an e-mailed statement. "This financing will help us accelerate our go-to-market strategy."