I would like to get any suggestions on detecting conference call for on going call. I looked at the documentation but didn't got any hint from it. https://developer.android.com/reference/android/telephony/TelephonyManager.html
The information his phone has regarding calls is not shared with your phone at any point doing the call or otherwise, it's shared with the towers. there will be no app or software or hardware for that matter that can do what you need unless it's police sting ray