I'm playing with new-style packaged apps in Chrome 24, and I don't see any way to bring up Developer Tools to do debugging.
What's the recommended strategy for debugging?
I've been able to right click the content area and inspect an element to get the dev tools to come up.
go to here
chrome://inspect/
find the page you want
Starting on Chrome 24, you can right click and inspect your page or inspect the background page.
If your app doesn't have any open window to right click, you can go to chrome://extensions and use the Inspect Views links, from where you can open Developer Tools for any of your app pages, including those in the background.
Before Chrome 24, the only difference is that the background page could only be inspected using the chrome://extensions link, there was no "Inspect background page" in the right click menu.
UPDATE: If you want to debug an app installed from the Chrome Web Store, you need to enable the flag "Enable debugging for packed apps" in the chrome:flags page:
After that, right click will work on any app.
来源：https://stackoverflow.com/questions/12583545/debugging-new-chrome-packaged-apps