So I was flying my Mavic Air today in 92F weather. Pretty typical temerature in my part of the world (Florida) and nothing I haven't done plenty of times before. After about 12-13 minutes of flying, my tablet (Galaxy S2 Tab) informs me that to prevent overheating, it's shutting down some apps. DJIGo was my only app open so of course it was shut down. The tablet would not let me re-open it until the overheating danger was gone. Awesome. Luckily, I was within visual range of my Air and still had full control of it with the controller, so I just flew back and landed safely.
My question is, what if I had lost visual or somehow became disoriented and couldn't find my drone in the sky? Since I couldn't open the app, what would you do in this situation of essentially flying totally blind? I had full GPS lock in the app and the home point was set correctly before I went anywhere. Would pressing the Home button on the controller still work even if the app wasn't running? The Air has no LCD display on the controller like the Mavic Pro. Is there enough info (height, heading, distance, etc) on the Mavic Pro controller to bring it back home if flying blind like that?

Yes, I know.. VLOS and all that, and I typically do fly in visual range, but sometimes I have a hard time finding it in a bright sky or especially if there is a busy background behind it.

Mavic pro screen shows altitude and distance from homepoint and at a push can be used to navigate back.

Even with the app disconnected RTH will work as normal.

Press RTH .

you've sort of answered your own question ;-)

If you can see the drone you can fly it and follow it, as the drone gets further away you can't tell the orientation, however the way it response to the right stick can tell you which way it's facing e.g. if the drone moves right when you push right it's facing away from you, if it moves away from you when you push right it's rotated 90 degrees etc

At the end of the day if all else fails there is a RTH button on the remote, if the app and remote have failed the drone will come back to the (set) home point.

Yes.  Pressing RTH on the controller will bring it back.  The return is not based on the app.  it is based on the GPS in the aircraft.

Thanks for the responses everyone. It's good to know that the RTH button works even when the app isn't running. I wasn't sure about that.

Hi, Thanks for your inquiry. In any case that the drone will be out of your sight, you can use the RTH button for your drone to locate the home point for as long as the compass and GPS are working fine, however, I would recommend doing a preflight checklist, ensure the environment is not a hazardous, GPS should be strong as well to prevent an incident. Remember that prevention is better than cure. Thank you for the support.

If you can see the drone you can find out it's heading by moving the left and right stick. If the drone move same direction with your stick it's back to you. If the drone move oppsite direction it's heading to you. If not moving it's 90 degree to you. Use the forwsrd and backword stick to further find out which way it facing. Turn the drone if not facing the right direction. When you see drone only move by push left and right stick but not movement by front and back stick, it's either head or back to you.