I find this live-chat widget is the simplest to use, and it's convenient as you can set up everything through Whatsapp, Telegram and Facebook Messenger.

When a visitor sends me a message, Replain sends a notification to my Whatsapp. As I always check my WhatsApp, I will not miss any single visitor who contacted me on my website using Re:plain.

It was a little confusing to set up at first. But, it is super easy once I know how. It's fully automated.

I'm glad to find this tool. Thanks, Dmitry, for assisting me with the setup progress.
You'll meet an arrogant operator(name starts with E.) some day when you chat with Re:plain for help or something else(I met this arrogant today); I hope he will be well-trained by Re:plain on how to attend to their customers.