I have a Galaxy Note 5 with a pretty nice, wide angle lense when it's in landscape mode.
I've checked the camera and how I use it on my dash and it's just right as a dashcam, however I want to still play podcasts, use google maps and so on.
Is there a dashcam app which will run in the background at say 1280x720 or 1920x1080 and just use 5 or so GB of space and over-write it as it goes?
Bonus points if it records GPS speed while filming.
I looked around but most of them seemed to want to keep the application open while using the phone.
I did this with the Samsung NOTE. I recommend against it.
Get a standard dashcam. It will make your phone not heat up, preserve its internal storage, battery capacity and screen burn-in.
Not to mention, its fitted more securely, so its less of a hassle or flying object if you're ever involved in an accident.
Or as a visible target to thieves who might get in your car (at lights, parked, or if Ubering)
And it'll also mean that you won't be seen by police touching your phone on the road, saving you fines and demerit points.