Social² provides you to open your second social account of most top social sites.
You can use WhatsApp on your iPad with this app and you can also have 2 numbers of WhatsApp on your iPhone.
Just like the web version of WhatsApp, the "Messenger for WhatsApp" is an extension of your phone, which simply mirror your conversations and messages as they are in your phone device, that means, all your messages remain originally saved on your phone.
Its simple to connect with whats app:
1 > Open WhatsApp on your iPhone
2 > Settings > WhatsApp web > Scan QR Code
3 > You are done!
Your phone must be connected to the internet for the "WhatsApp Messenger is" to work, and in addition, make sure you have the latest version of WhatsApp is available for your phone.