CryptoVox Push-To-Talk makes powerful encrypted many-to-many walkie-talkie communications easy to set up, and completely secure. Just enter a unique "channel" ID, and share your encryption password with your users to get up and running.
Message monitoring happens in the background, and the entire message history (with timestamp/user info) is re-playable and stored on the server. Pause playback and resume it later.
Be completely in control and host your own server, requiring no connection to the internet. A single server can host multiple "channels".
See
http://www.domain17.net/cryptovox
for more information.
Features:
Crystal-clear audio
Customer-hosted and cloud-hosted servers
AES 256-bit encryption (opaque to server)
Attractive/powerful UI
Speakerphone