Sipgate enabled iPhone users to make VoIP calls when connected to a local WiFi hotspot in Germany, which raised the anger of Apple’s German carrier, T-Mobile, which launched legal action to ban the app. The court agreed with T-Mobile that Sipgate had used unfair business practices in order to attract consumers that are otherwise locked to T-Mobile while making calls. The carrier also argued that because use of the application required that users jailbreak their iPhones, thus breaching their agreement with T-mobile.  It is not known how this will effect other VoIP apps in other markets.  Truphone comes to mind. And in related news, NetShare developers, Null River, confirmed this weekend that their popular iPhone tethering application won’t be made available again through the App Steore. And industry observers once again believe its the carrier – in this case, At&T – that’s to blame for the ban. “Looks like Apple has decided they will not be allowing any tethering applications in the AppStore,” Null River wrote. “As such, NetShare will not be available in the iTunes AppStore. We are seeing a lot of similar reports from various developers who’s applications were abruptly removed and banned from the AppStore without any violations of the terms of service. This is all unfortunate news for the iPhone platform end-users.” Also last week, iPhone app Podcaster was denied the chance to be sold through the App Store, with Apple saying the software “assists in the distribution of podcasts, it duplicates the functionality of the Podcast section of iTunes,” and citing that as cause for the rejection.