manifest.json

{
    "name": "Reticle",
    "version": "1.0.1",
    "manifest_version": 2,
    "description": "Drag and resize a ruler overlay to quickly measure pixel dimensions, positioning, and alignment of elements on any webpage.",
    "options_page": "settings.html",
    "icons": {
        "16": "images/icon-16.png",
        "48": "images/icon-48.png",
        "128": "images/icon-128.png"
    },
    "background": {
        "scripts": ["js/background.js"],
        "persistent": false
    },
    "permissions": [
        "activeTab"
    ],
    "browser_action": {
        "default_icon": {
            "19": "images/browser-action-19.png",
            "38": "images/browser-action-38.png"
        },
        "default_title": "Enable Reticle"
    },
    "commands": {
        "_execute_browser_action" : {
            "suggested_key": {
                "default": "Ctrl+Shift+X",
                "windows": "Ctrl+Shift+X",
                "mac": "Command+Shift+X",
                "chromeos": "Ctrl+Shift+X",
                "linux": "Ctrl+Shift+X"
            }
        }
    }
}