There is a way, but it's quite complicated to get it to work or rather it doesn't work well as your whatsapp is linked to your number.
I think if you are planning to only use it on your iPad then it should be ok, but I tried to use it simultaneously with my iPhone and that's when you get a lot problems! It wasn't worth the hassle.
I think I used a tweak called whatspad or something, not sure if it's compatible with ios7.
edit I just had a thought, if you are using a cellular ipad you may have a better chance at getting it to work.