Examine source code of Checkvist

{
  "manifest_version": 2,
  "browser_action": {
    "default_icon": "icon-128x128.png",
    "default_title": "View Checkvist Lists",
    "default_popup": "popout.html"
  },
  "description": "Quickly check your Checkvist without leaving the page, or open Checkvist in Firefox sidebar",
  "icons": {
    "48": "icon-48x48.png",
    "128": "icon-128x128.png"
  },
  "name": "Checkvist",
  "sidebar_action": {
    "default_title": "Checkvist",
    "default_panel": "sidebar.html",
    "default_icon": "icon-48x48.png"
  },
  "commands": {
    "_execute_sidebar_action": {
      "suggested_key": {
        "default": "Ctrl+Shift+X"
      }
    }
  },
  "version": "1.0.12"
}