These apps must have greatly improved over the years. The one I purchased and tried to use several years ago wasn't accurate, had a very small database of courses listed, and drained my cellphone battery quite quickly.
Nice to hear that the technology has finally paired nicely between the apps and the smartphones.
I'll still use my laser range finder, but mostly because our greens at my club are huge and the difference between front, middle and back hole locations could be as much as 10 yards in some instances.