It’s important to enable proguard in our project, so if a question arises in the form “should all android apps enable proguard?” I will say yes.
Because you will build a small-sized app, unused code removed and all identifiers changed to protect from decompiling apk.
What is ProGuard
ProGuard is a tool that shrinks, optimizes and obfuscates code, it is readily available as part of the Android Gradle build process and ships with the SDK.
1: it gets rid of unused code
2: it renames identifiers to make the code smaller,
3: it performs the whole program optimizations.
However, when you create a new project using Android Studio, shrinking, obfuscation, and code optimization is not enabled by default. That’s because these compile-time optimizations increase the build time of your project and might introduce bugs if you do not sufficiently
So, it’s best to enable these compile-time tasks when building the final version of your app that you test prior to publishing. To enable shrinking, obfuscation, and optimization, you will include the following in your project-level build.gradle file.
How to Setup Proguard
// Enables code shrinking, obfuscation, and optimization for only
// your project's release build type.
minifyEnabled true // Enables resource shrinking, which is performed by the
// Android Gradle plugin.
shrinkResources true // Includes the default ProGuard rules files that are packaged with
// the Android Gradle plugin. To learn more, go to the section about
// R8 configuration files.
When you use ProGuard you should always QA your release builds thoroughly, either by having end-to-end tests or manually going through all screens in your app to see if anything is missing or crashing.
also, some Libraries include Proguard/R8 guide to help protect some of the classes created to avoid missing classes example Retrofit