Exactly as it says on the tin, a webclient for your WhatsApp.
How it works:
Go to: https://web.whatsapp.com via GOOGLE CHROME only
Launch WhatsApp on your Android phone
Go to main menu, click on "WhatsApp Web"
The camera will launch asking you to scan the QR thingy
Boom! You're logged in
The web client acts as a mirror/extension of your phone. Your phone will still need to be connected to the internet in order for it to function. But if you hate typing on your phone like I do... and you spend a lot of time on a computer anyway; this is a lovely tool. I've ignored many unimportant messages simply because I cannot be assed to reply using my phone lol
Sorry Apple users: https://blog.whatsapp.com/614/WhatsApp-Web
Unfortunately for now, we will not be able to provide web client to our iOS users due to Apple platform limitations.