I have just set up an iPad mini 4 cellular on a yolk mount. I have a lightning lead attached which goes to a cigarette lighter in the aircraft. The advantage of the cellular is that it has internal GPS. You can buy an external GPS to fit into the lightning socket but if you do that, you lose the ability to power the iPad. The external GPS costs the same as the extra for the cellular iPad so for me it is a no brainer. The nano SIM card allows you to connect to 4g and get up to date met, notams etc. You could also tether your smart phone to the iPad and get the same info. Coupled to Skydemon it is a great piece of kit.