This is an example application that shows a Todo list that sync with a Google Spreadsheet.
Check out this repository and then host it from a webserver.
To spin up a temporary webserver to experiment, execute the following command from the project directory:
$ python -m SimpleHTTPServerThen visit http://localhost:8000.
Note that simply double-clicking the index.html file to open from your hard drive will not work because browsers handle the file:// scheme with a special set of security restrictions.