Call Flip (Between Devices) How to initiate a call flip (originating device) Make or receive a call using the Zoom desktop client, mobile app, or a provisioned desk phone. Place the call on hold using the in-call controls.The other party will hear hold music while they are on hold. How to answer a held call (destination device) Desktop client or mobile app Click or tap the Phone icon. Click or tap the Lines tab to see the call you have placed on hold. Click or tap the hold icon to answer the call.