Fring, the mobile communications and social networking aggregator, says that VoIP provider Skype is blocking all interconnectivity between the two services. But Skype says it’s not to blame.

According to a press release from fring, it is “being forced to stop its four years of Skype interconnectivity following threat of legal action.”

The news comes just days after fring announced that a new version of its iPhone app had been approved at the App Store. The new app allows users to make video calls over 3G, something the Skype iPhone app still lacks. Fring calls the move by Skype “anti-competitive ambush.”

Fring went so far as to call Skype “cowards” in a blog post on the company’s website:

“They are afraid of open mobile communication. Cowards.

Needless to say, we are very disappointed that Skype, who once championed the cause of openness, is now trying to muzzle competition, even at the expense of its own users.

We’re sorry for the inconvenience Skype has caused you.”

Skype says fring is the one causing the inconvenience.

An official statement from Skype said that “Skype is disappointed that an amicable resolution was not possible but Fring’s decision to withdraw Skype functionality immediately was of its own choice.” The statement goes on to say that Skype encourages developers to build products that work with Skype APIs but that it will “rigorously protect its brand and reputation and those companies that do not comply with our terms will be subject to enforcement.”

Skype and fring do compete in the same market, as both companies offer VoIP, IM and video calling services. Skype recently released a new iPhone app that will bring changes to the service come the end of the year. While Skype-to-Skype calling will remain free, users will be asked to pay if they want to make Skype calls to cell phones or landlines over 3G using the iPhone app. Pricing details for this feature are yet to be announced, as price testing is ongoing.

Google has released a new piece of software called App Inventor that allows lay users to create relatively complex mobile applications for the Android platform. According to a blog posted on Google’s website, the new system will allow users who don’t know a shred of programming to create apps by dragging and dropping commonly used “blocks” of Java code into a template.

App Inventor allows users to create apps that are sophisticated enough that they can store data created by users in a database. Users also can create apps that use GPS location information and automatically send text messages.

The blocks editor uses the Open Blocks Java library for creating visual blocks programming languages. Open Blocks is distributed by the Massachusetts Institute of Technology’s Scheller Teacher Education Program and derives from thesis research by Ricarose Roque. Open Blocks visual programming is closely related to the Scratch programming language, a project of the MIT Media Laboratory’s Lifelong Kindergarten Group.

The compiler that translates the visual blocks language for implementation on Android uses the Kawa Language Framework and Kawa’s dialect of the Scheme programming language, developed by Per Bothner and distributed as part of the Gnu Operating System by the Free Software Foundation.