For a given phone call, you would be abe to pull up the app and put the caller on hold, transfer it to another user/phone/contact and mute/unmute the call.

For an iPhone with a simultaneous voice + data connection (i.e. an iPhone that is roaming on wifi or a GSM iPhone, e.g AT&T)

• Switch from the live call screen to the Ringio app
• You would see a live all control screen
• Press the corresponding button
• Ringio performs the action