Used i pad 2 mini since I got my Mavic, no problems. reset to factory setting, just have DJI program running and don't forget to set it to flight mode to kill wifi and bluetooth.
Bought an i pad mini 2 on ebay second hand. Factory reset it to get rid of all the rubbish. Downloaded go4 and it runs perfectly for the last year or so. Set it to airplane mode to stop it from interfering with wifi.