Examine source code of Pieces

{
  "name": "Pieces",
  "description": "Save snippets, links, text, and more from around the web using the Pieces Firefox Extension.",
  "version": "0.0.1",
  "manifest_version": 2,
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "activeTab",
    "tabs",
    "bookmarks",
    "history",
    "menus",
    "*://localhost/*",
    "https://pieces.app/*"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "./16x16.png",
      "32": "./32x32.png",
      "48": "./48x48.png",
      "128": "./128x128.png"
    }
  },
  "icons": {
    "16": "./16x16.png",
    "32": "./32x32.png",
    "48": "./48x48.png",
    "128": "./128x128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "https://pieces.app/*",
        "*://localhost/*"
      ],
      "js": [
        "boot.js"
      ]
    }
  ]
}