I use the generic notes app on my galaxy phone. I used to use a 3rd gen iPad years back, maybe just for street cred. I guess it depends how in depth you want or need to get on a consult. I just walk room by room with the prospect and say something to the effect of "thanks, I'm going to take some notes as we go..."
"There's a big difference between winging it and seeing what happens. Now let's see what happens." ~MacGruber