Do these systems update distance based on where the flag is?
I currently use the hole19 app, mostly because it is free! But I find that get so sick of having to take my phone out constantly to update shots and I find that the distance reading is to the middle of the green and if I want to adjust it to the position of the flag I have to take my phone out yet again. I've found that I'm back to square one, using the course score card and pencils and then using the app just for distance estimates.
This would be a upgrade from my current system but if it doesn't take into account changing pin positions I may be looking at just getting a range finder and continuing with the trusted pencils and paper! Especially given that this will not be cheap!