On IPad the local latency correction only can be done manually. 

Follow these steps:

  1. Start a session with your student 
  2. Open the apps with the mixer-tool. 
  3. Switch Playdirection to student 
  4. Switch on "Remote" in the Metronome and set tempo to about 60 bpm 
  5. Start the metronome and let the student clap to the click 
  6. If the student is clapping behind the click the student has to increase the latency correction in his mixer with the +/- Button - If the student clapping is in front the student has to decrease the value until the coach hears both signal in sync.

The value is stored automatically. 

In example a Macbook with the internal soundcard has a latency value of about 0,116s - If you use an iPad with EarPods the value is about 0,440s

Also check this, please:

How to calibrate the "local latency" manually?