RedPhone has been folded into Signal. Please install Signal instead:
★ RedPhone has moved to Signal!
★ Add IPv6 support for T-Mobile devices on IPv6-only APNs.
★ Mute music applications when incoming call comes in.
★ Bug fixes.
★ Major improvements to audio quality.
★ Only display contacts with RedPhone installed.
★ Add a manual dialer.
★ Fix for SELinux bug on S4.
★ Support an option to disable bluetooth.