This is my rig. It's a iPhone X. I'm using Filmic Pro which is a great app that allows to control almost any function of the built in camera.

Since smart phones don't have a iris I'm using a variable ND or gray filter in order to keep the exposure time at 1/50 if the light is too bright. In addition I'm using a Manfrotto fluid head which allows very smooth panning. I'm also working on a DIY dolly.

I'm shooting with Mavis Pro. It's far more user friendly than Filmic Pro and has some great zoom functions that allow to dig into the 12 MP sensor of the iPhone. On the right side you can see a iRig II HD microphone.