The main APP you will need while in China is WeChat!
It's a combination of SKYPE, Facebook, Instagram and Apple Pay all bundled into ONE!
You could pay for meals, taxi's, bar, KTV, hotel rooms, etc.. on WeChat Pay. However, you will need a Chinese phone number and bank account in order to get your "WeChat Pay" going. It's the most convenient APP you will ever use!
Is great if you plan on staying here for over six months to a year! You could pay all your utilities automatically on this APP! As well as pay for everything else on the run!
Allows you to communicate without a problem! Explore the APP and have fun with it. Baidu China's Google! So if you have used Google translate, you will be familiar with Baidu
Anyone with a passport and VISA could open a bank account. No money is required to open a bank account in China. However, you will need a Chinese phone number. These APP's listed will help to make life easier for you when in China.
There are other APP's but these three are the main ones any foreigner uses to make life easier while in China!