Certainly wish I could help. I'm still tracking iCall who claim to have a working version in beta but don't respond to my emails asking for possible release dates. They are (bless their simple hearts...) trying to get it into the crApp store, so it's as likely as not that the delay is Apples fault.
This sounds like a perfect rendition of the VoIP application tho.
Quoting an answer to a similar question on the Fring forum: "The answer is no. The previous version was a pre-release version when there was nowhere else to publish apps. Now there's an official place for that, there's an SKD from Apple... we go that way."