I use Skydemon on an iPad 2 and copy the Skyedemon produced route and plog details onto the paper chart and also put the basic plog details on a paper plog for my kneeboard (I don't have the facility to print a plog etc from the iPad when planning at the airfield).
The ipad goes on the other knee, so I have the option of using the paper plog and chart as my primary means of navigation with Skydemon as a back-up, or vice versa.
However, the magenta line is very seductive and I find myself drawn to it. If it works properly, it removes most of the guesswork from navigation, but I'm sure it removes the skills too.
I've had had one iPad overheat this year - the iPad shut down for the last 30 mins of a flight that was close to controlled airspace. I was grateful that I had the back up of the paper chart and plog - without them I would have been well outside my comfort zone!