Chrome Extension (Plugin)

You can create small extensions that customize the browsing experience for Chrome. On Chrome, the extension/plugin appears as a small icon to the right of the address bar.

Create a directory. Add the files manifest.json and hello.html. You can include JavaScript in the HTML file too.
{
    "name": "Hello Extensions",
    "description" : "Base Level Extension",
    "version": "1.0",
    "manifest_version": 2,
    "browser_action": {
      "default_popup": "hello.html",
      "default_icon": "hello_extensions.png"
    },
    "commands": {
      "_execute_browser_action": {
        "suggested_key": {
          "default": "Ctrl+Shift+F",
          "mac": "MacCtrl+Shift+F"
        },
        "description": "Opens hello.html"
      }
    }
    }

<html>
    <body>
      <h1>Hello Extensions</h1>
    </body>
  </html>

To publish your item to the Chrome Web Store, follow these steps:

1. Create your item's zip file

2. Create a developer account

3. Upload your item

4. Add assets for your listing

5. Submit your item for publishing