I kinda liked it better when the devtools protocol was bundled directly into web app tester so I didn't have to actually have all the android SDK stuff on my box, but there we are. I liked the Amazon web app approach because it had taken so much of this complexity off of the process.
In any case, following the instructions at https://developer.amazon.com/docs/html5-web-apps/webapp-debug-app.html#install-adb and I'm hitting the blocker at running adb
./adb forward tcp:1234 localabstract:com.amazon.performancetester.devtools
and i'm getting the reply
error: device '(null)' not found
Nothing I've tried to install via ./android has solved this.