You can directly open index.html
to launch this dApp locally. There is no need to start a web server. This dApp does not require Internet access either. It only communicates with the Whisper node running on your local machine.
MAKE SURE there is a running Whisper v6 node exposing a WebSocket RPC interface at URL ws://localhost:8546
before running! This dApp will not display an alert if it fails to connect to a Whisper node. If you don't know how to do it, please refer to this wiki article.