Fring has released a version of its VoIP application for the iPhone even though it will only be available to customers who have unlocked their handsets for now.

Fring, a mobile internet service and community, enables users to access and interact with their social networks on-the-go, make free calls and live chat with all their fring, Skype, MSN Messenger, Google Talk, ICQ, SIP, Twitter, Yahoo and AIM friends using a handsets internet connection rather than costly call minutes.

Users will be to talk, chat and interact with other fring users and all of their online communities, using their iPhone's Wi-Fi connection.

The special pre-release version will enable iPhone users to get an early taste of fring regardless of whether they are on their mobiles, PCs or other internet devices.

Fring is expected to release a full version of the software in June when Apple releases an update to its iPhone.