This is a little extension to help switching to and from app/pinned tabs.
To install and test out:
git clone https://github.com/ianb/quick-switch-extension.git
cd quick-switch-extension
npm install
npm start
IRC is the best way to communicate, via #testpilot
on irc.mozilla.org (you can use this link for chat access via the web if you do not otherwise use IRC). You might want to ping ianbicking