Obfuscating your app

To obfuscate your app, use the flutter build command
in release mode
with the --obfuscate and  --split-debug-info options.
The --split-debug-info option specifies the directory
where Flutter outputs debug files.
In the case of obfuscation, it outputs a symbol map.
For example:

flutter build apk

-obfuscate

-split-debug-info

=/<project-name>/<directory>

Once you’ve obfuscated your binary, save
the symbols file. You need this if you later
want to de-obfuscate a stack trace.

Tip:
  The --split-debug-info option can also be used without --obfuscate
  to extract Dart program symbols, reducing code size.
  To learn more about app size, see Measuring your app’s size.