Israeli-based Fring has closed a second round of funding for an estimated $12 million. The round was led by US VC fund North Bridge Venture Partners, with VenFin and previous investors Pitango, Veritas and Yossi Vardi also participating, reports TechCrunch. Fring sends the calls or chats over Wi-Fi or 3G, with a nominal fee to call standard phone lines. The service works on Windows and Symbian devices and connects to other SIP based VoIP clients and instant messaging services. It’s a pretty solid second round for a mobile VoIP company.