The "Download Now" link directs you to the iTunes App Store, where you must continue the download process. You must have iTunes installed in order to open the link, and you must have an active iTunes account to download the application. This download may not be available in some countries.
From Shah Communications L.L.C:
Please create an account on www.allabouttalking.com in order to use this software. With this application, user can make and receive VOIP calls from iPhone/ iPod Touch/IPad directly through the internet via 3G, EDGE or Wi-FiMain features:* Making and receiving SIP calls* Connectivity through 3G, Edge and Wi-Fi* Free calls among users* Built-in tunnel for passing thru voip blockades* Integrated contacts from the phone* Loudspeaker* Favorites* Balance information* Call cost information* Destination, rate* Time, call status logs* Last calls log* Redial* Support for codecs g.729, GSM and g.711* Compatible with IPod Touch 2nd generation and IPhone 2G/3G* iPhone's address book integration* Direct access to voicemails* XMPP chat and presenceNote:1. You need to have account from www.allabouttalking.com in order to use this software.2. For iPod touch 1st generation users, you need upgrade your iPod to iPhone/iPod OS 3.0 or above and you also need external microphone.3. Please, check your cellular operator's terms of agreement to make sure they allow sip calls on their network before using our service.