TLDR; Optimisation features of Proguard can be useful for removing some "obfuscations" that add dead code and screw up control flow.
Proguard comes with Android Studio or can be installed from homebrew on Mac, that one version is newer:
$brew install proguard
Then use a generic script similar to this one:
Run as proguard @deob.conf and you'll end up with a more readable version of your obfuscated code.