What is GBWhatsApp?

Well, that's up to the amateur. I don't know if you can use gb whatsapp, because it is very similar to its "official" brother. Its main difference is the invisible mode. It allows you to hide time online, read-not-read messages, doesn't show your conversation partner when you're typing a message. But some people just don't need such tricks and they have enough of the usual version. But I personally only use this mod.