Smartphones get all the buzz, but mobile app warehouse GetJar claims that 90 percent of phones in use worldwide, and 72 percent of American phones, are still the non-smartphones that the mobile industry confusingly calls “feature phones.”

To make money from them, according to Patrick Mork, an executive at a leading app store for feature phones, app makers need to create Java-based apps that are free to download, and that make money from ads rather than through an upfront price.

“There’s been a perception out there that you have to be a fairly large brand, or you have to have very deep pockets, in order to succeed in an app store,” said Mork, GetJar’s vice president of marketing, told me in a phone interview. “But developers are realizing that if they want to grow internationally. they have to have a free app. It’s much easier to start with a Java app and then move to Android and iPhone than it is to go the other way around.”

Mork cites the example of Israeli startup Snaptu, whose eponymous suite of apps for Twitter, Facebook, news-reading (there’s a TechCrunch app), and other mobile services are one of GetJar’s top ten downloads. Snaptu apps make money by serving mobile ads through a collection of networks — BuzzCity, Millennial Media, Inmobi, AdMob, Amobee and others.

Java, more specifically the J2ME mobile version of Oracle’s software platform (it was developed by Sun, which Oracle now owns), works on most low-end phones worldwide. These phones are uncool among technophile Americans, but popular in other countries where people make less money and wireless carriers don’t subsidize the price of BlackBerrys, iPhones and Droids.

The biggest problem with Java is that it doesn’t really work on smartphones. Java’s creators envisioned it as a “run-anywhere” programming language, not restricted to specific hardware or operating systems. But years later, Android phones don’t support J2ME out of the box, and Apple demands that apps be written with Apple’s own non-Java software tools.

One reason is that apps written specifically for one type of phone, “native apps” in developer-speak, can take advantage of many software hooks not available to Java programs designed to work on a much wider array of phones. So, developers who start out in Java may still need to create separate versions of their apps for iPhones and Android phones. And BlackBerry phones, where Java apps frequently lock up my late-model BlackBerry Curve with error messages that require a reboot.

Still, Mork says that many GetJar customers — some of whom pay GetJar to place their free apps prominently, so they can make money off ads to those who download them — began as smartphone developers, then “realized that they needed to broaden to feature phones if they wanted to make a profit.”

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