Keep in mind, that many webpages are blocked by the "Great Firewall of China". Basically all kind of "naughty pages" will not be available within China. Because of political reasons, there are also many popular non-erotic web services blocked, like for example all Google services (including Youtube and GMail). Also Twitter, Facebook and other pages are blocked. If you want to access these pages, it is best to acquire a VPN service. Two of the more popular paid VPN services available are Nord VPN and Astrill VPN.
So far this page is not blocked in China, however the server is in Iceland (Europe) so it can be that you sometimes need to be more patient, as the data has to travel half the world.
Whatsapp is severely crippled in China. Although very occassionally messages seep through, pictures and attachments cannot be transferred at all. You can also get a VPN on your mobile phone, if you really require WhatsApp access. You need to know, that almost no one in China uses Whatsapp. Chinese people are all using a domestic developed chat application called WeChat.If you want to get in touch with local people (which is for example necessary to visit a sauna club or contact an independent escort), you will need to use WeChat.
In fact Wechat is quite a good chat application and easy to use. It is very similar to WhatsApp, and in fact WhatsApp has been copying a few functionalities off of WeChat the last few years. It has a built in translator, which tremendously helps you to communicate with anybody who doesn't speak english. It also allows you to send pictures, short video's and (real time) locations. One thing you have to keep in mind, WeChat accounts are linked to your phone number. If you are using a Chinese phone number, you very likely had to give your passport copy and address to the provider. Which means they know who you are and where you live. If you do illegal activities on WeChat, which is linked to your phone number, it means the police can track you down, if they wanted to. If you are using a non-chinese phone number, or a pre-paid card, you should not have this issue. Unfortunately China does no longer sell pre-paid cards.
You can get WeChat from the Apple Store or the Google Play Store