When Lotte Card, one of South Korea's biggest credit card companies, wanted to create an augmented-reality app earlier this year, it faced a familiar conundrum: whether to develop a sophisticated custom app for each major mobile platform out there or produce a single less-capable Web app that works on any device via its browser. In the end, the company decided to do a bit of both.

With the help of mobile application platform Worklight, Lotte's programmers created hundreds of HTML-based pages using standard tools—HTML5, CSS, and JavaScript—and then wrapped them up in native iOS and Android code so that the resulting bundle could be delivered, just like any other app, via the Apple and Android app stores.

The key advantage of Web apps over native mobile apps is cross-platform compatibility. They run in the standards-compliant browsers that are available on Android, Apple, BlackBerry, and Windows mobile devices, so (in theory at least) they have to be built only once. The disadvantages are that they lack access to such features of a device as the camera and the address book, they can't use some of user-interface elements that are native to each platform, and they can't be downloaded from Apple's App Store or the Android Market.

Most native apps can tap into the device's browser, in order to grab content from the Web. As the variety of mobile platforms grows, more companies may be drawn to using this capability, creating hybrid apps that use Web technologies but can be distributed via the usual app stores.

"The slickness of the user interface a developer can achieve in the native [app] model just isn't worth the extra spending compared to the very nice level of user-interface experience they get from the hybrid option," says Ron Perry, CTO of Worklight. Worklight uses the open-source PhoneGap platform to help developers package Web apps within native apps so that they can be downloaded from app stores.

The primary competitor to PhoneGap is Appcelerator's Titanium Studio, a development environment that takes a slightly different approach. Instead of showing Web content within an app, this platform recompiles a Web app's (JavaScript) code into native code that can access all the device-specific user-interface elements of iOS, Android, and BlackBerry's platform. (It is not yet compatible with Windows Phone.)