Packet8 MobileTalk for iPhone

On the other hand, 8x8 Inc.'s VoIP application, called Packet8 MobileTalk for iPhone, doesn't use wifi but does use the cellular voice network to carry calls between the handset and the VoIP network. To do so, the app eschews the downloaded client software that 8x8 uses to provide MobileTalk to users of other cell phones (which also means that it's not actually an App Store application). Instead, Packet8 MobileTalk for iPhone employs a Web portal, which is accessible through the iPhone browser, that mimics the iPhone dialer.

To establish the connection once the user has entered the number, the portal reads a cookie that the browser has stored in order to determine who is making the call. The portal then sends the browser an instruction that causes the iPhone to dial a local Packet8 access number. From there, the call travels over the Packet8 VoIP network. The portal-based approach is necessary because third-party apps cannot directly access the iPhone dialer, according to 8x8's vice president of engineering Ramprakash Narayanaswamy.

JAJAH's iPhone App: Coming Soon

JAJAH Inc.'s iPhone VoIP app — like many iPhone apps of all kinds — is still awaiting Apple's OK before users can download it through the App Store, but it should be impressive once it is released. According to JAJAH co-founder Roman Scharf, the app will allow iPhones to make calls that travel over 3G, EDGE or wifi data networks to reach the JAJAH VoIP network. A call goes over the data network if the quality of that link is sufficient or if the user specifies that it do so regardless. Otherwise, JAJAH calls the iPhone and the overseas number that the user is trying to reach and connects the two calls via a VoIP link — a classic VoIP callback approach.

iCall App in Beta

ICall Inc.'s planned iPhone application is still in beta testing. Like Truphone's app, it will use wifi links to access the VoIP network. A unique feature is the app's ability to switch from a cellular call to a wifi call without interrupting the conversation. ICall claims that such transfers will happen "seamlessly." CEO Arlo Gilbert said that the application should be available in early August 2008.