Mobile ad network startup StartApp, which specializes in the distribution and monetization of Android apps, has secured over $4.3 million in funding in a round led by Ascent Venture Partners with participation from previous backer Cedar Fund.

Basically, StartApp provides Android smartphone owners with an additional search option and browser bookmarks, after they install apps that have integrated the startup’s solution.

When users search the Web with their engine, StartApp makes money, thus allowing them to pay developers per app download. The upside for developers is that they can keep their apps free of charge and/or ad-free because they monetize downloads directly regardless of price and in-app payment options.

How much do developers get per download? The answer, from StartApp’s FAQ:

We base our payment on your app downloads – you get paid for each download generated with our SDK inside. There are 2 integration levels available – Full and Partial.

The payment depends on the integration level you choose. On full – we pay $0.05 for each unique U.S install and $0.01 for each install from any other country. On partial – $0.04 for U.S and $0.008 for any other country.

The upside for users is less clear, and depends greatly on the quality of the search engine that gets installed on his or her smartphone. Personally, I’m always wary of things like this, because it reminds me of the days when you’d install new software on your desktop only to find new, often unwelcome features added to your browser.

In this case, however, users can easily delete the new search option or erase the bookmark links if they desire to do so.

StartApp says developers have already implemented its monetization solution into 1,500 Android apps, which have collectively achieved more than 50 million downloads. Notably, this feat was achieved in just six months after the fledgling company’s launch, which occurred in September 2011.

The company says it will expand to support other operating systems other than Android in the future.

Based in Israel, StartApp was founded in December 2010 by serial entrepreneurs Gil Dudkiewicz and Ran Avidan.

StartApp