Buy this app. – Cadrage Director's Viewfinder Review

If you’ve ever wanted to scout shooting locations without having to drag along your entire kit, stop reading this review and just buy this app already. It is the single most useful app in my professional arsenal: wherever I am, whatever I’m doing, I can grab my phone and instantly frame up a shot for any camera, lens, or aspect ratio. Better yet, Cadrage captures an incredibly useful amount of metadata so there’s no second-guessing how you got that shot. From time to GPS location to even the direction and orientation you were shooting, there’s so much data available that you can easily return to the location and set up without excessive re-scouting.
Review by Monsoon Season on Cadrage Director's Viewfinder.