Find the optimal solar panel tilt angle(play.google.com)
play.google.com
Find the optimal solar panel tilt angle
https://play.google.com/store/apps/details?id=com.secondtech.optimalsolarpaneltiltangle&hl=en_US
https://play.google.com/store/apps/details?id=com.secondtech.optimalsolarpaneltiltangle&hl=en_US
Just align the phone screen with a real or assumed solar panel and instantaneously get how close to the optimal efficiency is achieved at that angle.