I have a react-native app that I want to measure the data usage per user and gather them to optimize it later.
I saw old questions for native android suggesting that trafficStats may give stats by UUID.
What possibilities are there for react-native?
Using react-native means that you have two options,
The native implementation which depends on the OS you're working on.
If you're using a JS library for networking (Axios) or even a builtin function (fetch) you can implement a wrapper Promise which calculates the length of any input/output string, + an approximation of the length of the header.