Ventriloid is an open source VoIP client that connects to Ventrilo 3.x servers via WiFi or your cellular data plan.
I've noticed some people have been skeptical to update due to the new required permission allowing the app to read the device's call status and identity. This permission is only required in order to properly disconnect the user from the server in the event of a incoming/outgoing phone call, and then reconnect when the call is over. If you have any questions about this, please feel free to email me, as I cannot respond to reviews.