manifest.json

{
  "manifest_version": 2,
  "name": "My Custom Browser Tools",
  "description": "Develop, debug, and support my webapp.",
  "version": "0.1",
  // this allows iframes embedded within popup and dev tools to connect to the extension for messaging (in lieu of a content script)
  "externally_connectable": {
    "ids": [ "*" ],
    "matches": [
      // These are required for the content pages to connect to the extension (at least for now)
      "*://*.my-domain.com/*",
      "*://*.my-test-domain.com/*",
      "http://localhost:8080/*",
      "http://my-awesome-machine:8080/*"
    ]
  },
  "background": {
    "scripts": ["js/background.js"],
    "persistent": false
  },
  "devtools_page": "devtools.htm",
  "page_action": {
    "default_icon": "images/icon.png",
    "default_popup": "popup.htm"
  },
  "default_locale": "en",
  "permissions": [
    // Used to detect when to show the page action
    "webNavigation",
    "tabs",
    // Using wildcards to allow for varying local machine names. Pages are filtered in background.js for popup and content scripts
    "http://*/*",
    "https://*/*"
  ],
  "icons": {
      "16": "images/icon.png",
      "48": "images/icon.png",
      "128": "images/icon.png"
  }
}