Hey guys. Came across this website that I think could be usefull for measuring roofs from home. I know it sounds crazy but check out this website and look at the demo. Designed for landscapers but I see value in roof cleaning industry.
Looks like a high quality google map that you can switch to different angles and measure height of house, pitch of roof etc. Can also look straight down and figure sq. footage then figure for pitch. Costs around $1.50 or so per house. If house has a lot of trees I would imagine it might be a little difficult. Great for commercial jobs though!