Examine source code of Feeder

{
  "name": "RSS Feed Reader",
  "short_name": "feeder",
  "version": "7.7.3",
  "manifest_version": 2,
  "description": "Get a simple overview of your RSS and Atom feeds in the toolbar",
  "icons": {
    "19": "icons/icon-retina.png",
    "48": "icons/icon48x48.png",
    "128": "icons/icon128x128.png"
  },
  "browser_action": {
    "default_icon": "icons/icon-retina.png",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "js": [
        "content/content.js"
      ]
    },
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "all_frames": true,
      "run_at": "document_end",
      "js": [
        "content/page_plugin.js"
      ]
    },
    {
      "matches": [
        "http://feeder.co/*",
        "http://*.feeder.co/*",
        "https://feeder.co/*",
        "https://*.feeder.co/*"
      ],
      "run_at": "document_end",
      "js": [
        "content/feeder_api.js"
      ]
    }
  ],
  "intents": {
    "http://webintents.org/view": [
      {
        "type": [
          "application/rss+xml",
          "application/atom+xml"
        ],
        "href": "/options.html?with_intent=feed",
        "title": "Subscribe to feed using Feeder",
        "disposition": "window"
      }
    ],
    "http://webintents.org/subscribe": [
      {
        "type": [
          "application/rss+xml",
          "application/atom+xml"
        ],
        "href": "/options.html?with_subscribe_intent=subscribe",
        "title": "Subscribe to feed using Feeder",
        "disposition": "window"
      }
    ]
  },
  "background": {
    "page": "main.html"
  },
  "background_page": "main.html",
  "web_accessible_resources": [
    "icons/icon48x48.png",
    "icons/bar-buttons-good_2x.png",
    "icons/icon-retina.png"
  ],
  "options_page": "settings_redirect.html",
  "commands": {
    "_execute_browser_action": {
      "suggested_key": {
        "default": "Ctrl+Shift+R",
        "linux": "Ctrl+Shift+R",
        "windows": "Ctrl+Shift+R",
        "mac": "Alt+Shift+R"
      }
    }
  },
  "permissions": [
    "tabs",
    "http://*/*",
    "https://*/*",
    "chrome://favicon/",
    "storage",
    "notifications",
    "webNavigation",
    "webRequest",
    "webRequestBlocking",
    "unlimitedStorage"
  ]
}