Jetman, Given that the aircraft I fly, C172, all have ships GPS fitted, not surprisingly I use it for VFR nav assistance. Being old fashioned I still like the 3 Cs, Chart, Compass and Clock. In the air I use my iPad with OzRunways more like a chart, meaning I take a look at the displayed map and find landmarks just like with paper charts. If however I am navigating close to DME steps, zone boundaries et al I turn on own ship position and take a peek at the moving map position just in case. Hence my iPad is asleep most of the time and overheating has never happened to me in the air. I always carry a spare power source for the iPad.
I use OzRunways just because it's the first one I tried and I find it intuitive to do flight planning, fuel ordering and weight and balance. I'm reliably informed that Navplan is just as good.