I have used an iPad 9.7, 5th Gen, with no problem at all except for the fact that it gets too hot sometimes. I just bring the drone down when this happens and rest my iPad to cool down for a few minutes before starting it up again.
Welcome to the forum from out here in California, LA area. You’ll find tons of infos in here to your questions, just ask or post them. Also, people here in this forum are real good, respectful and very helpful ... Have fun flying and good luck!