I've found that with Papa John's pizza you can significantly improve the texture and flavour by letting it cool then heating it in a frying pan with a lid.

Cold pizza reheated in a Cast Iron Skillet with just a dash of olive oil is the best thing in the world.

I used to do that, but I've started using a toaster oven (400 degrees Fahrenheit for 6 or 7 minutes) now that I have one.

The skillet (understandably) doesn't heat the top of the pizza that much. The toaster oven doesn't have that problem.

skillet is for crisping up the bottom, add a lid or a circle of aluminium foil to get a nice bubbly cheese top

Pan-frying was the original Neopolitan way to make pizza. Learned that from an Italian work-colleague whose family back home still made them that way.

That's really interesting because I just discovered this the other day. I don't have an oven (living in Japan). I've got a frying pan and a fish grill. Heat up a frying pan with a lid on. Put in the pizza. Wait a couple of minutes (doesn't take long). Finish it under the grill. It's surprisingly good!