Gizmo is the best available alternative to Skype for making low-cost calls and sending text messages all over the world.
Since it’s based on open standards, Gizmo can be used from any smartphone compatible with WiFi SIP technology. Access the program’s website to download a version adapted to your model.
Gizmo lets you record voice conversations, use custom avatars, keep a history of all your chats, and it provides a voicemail service for when you can’t answer a call.
The application also includes an instant messaging client compatible with the networks of MSN Messenger, Google Talk, MySpace, iChat, Yahoo, and AIM, so you can hold group chats, transfer files, and make video calls.
For Mac OS X 10.3.9 or later.