Examine source code of TCGPlayerToCad

{
  "manifest_version": 2,
  "name": "TCGPlayerToCad",
  "version": "1.3",
  "description": "Display TCGPlayer.com prices as (CAD$) Canadian Dollars.",
  "icons": {
    "48": "icons/border-48.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.tcgplayer.com/product/*",
        "*://*.tcgplayer.com/search/*",
        "*://*.tcgplayer.com/sellerfeedback/*",
        "*://*.tcgplayer.com/*/decks/*",
        "*://*.tcgplayer.com/*/decks/",
        "*://*.tcgplayer.com/*/decks",
        "*://*.tcgplayer.com/*/deck/*",
        "*://prices.tcgplayer.com/price-guide/*",
        "*://*.tcgplayer.com/*/events/event/*"
      ],
      "js": [
        "usdToCadProduct.js"
      ]
    }
  ],
  "permissions": [
    "<all_urls>"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{13e92eef-4b0e-4efe-868f-54da76a553f0}"
    }
  }
}