Well most may know that you won’t be able to access the blocked apps in China like Facebook and Instagram and the list of blocked websites is here and also here (This site lags). Even if your favourite site is not blocked, it’s possible that the loading time will be slow. You may ask your ISTD friends why.They said in Rome, do what the Romans. So in your interest, just download the friendly apps in China. Downloading the first app of every category will be sufficient. Download the others for extra.
Links are for Android Users who cannot access Play Store (Links are not Updated). Apple users can access App Store.
In order of my popularity,
Web Messaging Apps (Whatsapp is Still Accessible)
Online Payment Apps
Check 4G Data Remainder App (Varies from Telecom)
This is the App Culture in China. Time to be IT Savvy. Just like how Apple like to say it. “There is an App for Everything”