Memo to developers whose languishing apps need a shot of adrenaline: The two guys who founded L.A.-based Maple Media now have a pile of cash to buy up underperforming mobile apps and — they hope — spin them into digital gold.

Maple Media, headed by entrepreneurs Michael Ritter (above right) and Clark Landry, has closed a $30 million investment from private-equity firm Shamrock Capital. The funding is the startup’s only outside investment. Maple Media’s mission is to acquire, manage and operate mobile applications spanning entertainment, games, utility and productivity categories.

Maple Media currently has a portfolio of about 150 apps, which generate several billion monthly mobile ad impressions, and the company claims it’s already cash-flow positive. Ritter, Maple Media’s CEO, declined to identify any of the apps.

Ritter said the idea for Maple Media came to him when he worked at mobile-games publisher Jam City (formerly SGN). As senior VP of business and corporate development, he saw many high-quality apps in the market – but that “developers don’t have skills to manage them.”

“We can help increase the performance of these apps, by improving retention and monetization,” said Ritter.

Landry, who is Maple Media’s COO, was an early investor in ad-tech companies Traffic Marketplace (acquired by Vivendi), Adconion Media Group (acquired by SingTel), and TheTradeDesk, along with mobile-games company Scopely. In addition, Landry has cofounded several startups including Shift (acquired by Brand Networks), TagWorld (acquired by Vivendi), and Minds & Machines.

The Century City, Calif.-based startup has six employees, and it’s looking to staff up with the funding. But the vast majority of the $30 million Maple Media banked will be used to acquire apps, according to Landry.

The company is using more than 20 metrics to evaluate which apps to buy, including number of active users, ratings, time spent and daily visits, and user attrition rate. Ritter said Maple Media is targeting apps with at least 20,000 daily active users. There’s a particularly rich opportunity to partner with app developers outside the U.S., he added: “We have clients on five continents.”

Shamrock Capital, which has $1.8 billion of assets under management, invests in media, entertainment and communications sectors. Its current investments include Appetize, FanDuel, Questex, Recorded Books, Screenvision Media, Silvergate Media and Wazee Digital. The funding in Maple Media was led by Shamrock partner Alan Resnikoff.