Apple has approved an app for Vonage's VOIP technology, Vonage announced on Tuesday. But what exactly does it do?

Apple has approved an app for Vonage's VOIP technology, Vonage announced on Tuesday.

In a tersely worded statement, Vonage said that its mobile application had been approved for the iPhone as well as the iPod touch.

"Vonage is currently conducting a beta test and general availability will be announced at a later date," the company said.

Vonage did not disclose what the app will actually do. Apple has rejected apps before that compete with its own services, but has approved VOIP apps that place calls on Wi-Fi. "Michael," who publishes tweets under the handle Vonage_Voice for Vonage, said he could not disclose what the app actually does for competitive reasons.

Vonage already provides voicemail transcription with some plans, and will email audio recordings of voice mails to a selected email address. It wasn't clear if the app will simply perform these functions, or allow users to place calls.

Voange has experimented before with peripherals that allow users to take calls on the road. Amazon.com, for example, still sells the Vonage V-Phone, a USB drive that gives a laptop or PC VOIP functionality. But the V-Phone has largely disappeared from the Vonage Web site, as has Vonage Talk, a click-to-call functionality that integrated with Microsoft Outlook.