Whenever I try to use the djigo 4 app with my iphone 6 it crashes, that doesn't happen when I use my ipad, it works perfectly . The problem is that when I use the app without connection to the controller the app works, as soon as I connect it crashes (the controller works ok) . I have tried everything, reset my iphone, reinstall the app etc , nothing works

You say you've reset your phone, do you mean you restored it to factory settings?

Could you please find the crash log by below path: /DJI GO 4/LOGS
Please upload it to dropbox and send me the link. I'll help to report it.