I came across this as I searched around for a good charging cable to keep at work/in-car besides the one that came with my Nexus 6P. Then I read about the Google engineer who had been reviewing all these cables and apparently they are not meeting standards and in one of those comments, I started to see this app being mentioned which basically tells you if your charging cable is USB-C standard compliant or not. I'll probably use it till I settle on a good cable.