Last month, VoipSwitch released Vippie for iOS and Android devices. The free VoIP app, which offers free texting (with attachments), push notifications, and free voice and video calls, has already reached 100,000 downloads through iTunes and the Android app store at Google Play.

Vippie offers free services to in-network users through 3G, EDGE, WiFi, and GPRS network connections, and doesn't require registration or a separate phone number. Vippie also supports low-cost VoIP out-of-network calls.

VoipSwitch's summer promotion features free calling to out-of-network users in the US and Canada through August, as long as Vippie users 'like' the app on Facebook.