I was just thinking about how the Scout Book app is a ways from keeping up with patrol-method requirements tracking. (E.g. PL's can't sign-off on requirements. Although they claim they may add the feature at some point.)
Consider the following low-brow high-tech procedure:
Each scout (or his parent) creates an account on the cloud (e.g. Google Drive) ... maybe with a folder labeled 'Rank Advancement '.
The scout gives 'read' rights to the folder to his SM, advancement chair, and parents.
After some requirements get signed off in his hand book, scout saves a photo of that