• Androidis a Google-led open source mobile operating system and open source project.
• It might be the simplest to locate the source: Build -> Analyze APK -> Select the apk you want to decompile in Android Studio 2.3. Its source code will be visible.
• Navigate to Tools -> Android -> SDK Manager in Android Studio. After that, you'll need to download the Android SDK Sources as stated below. After you've downloaded the sources, look for the source code in your SDK's 'sources' folder (wherever that may be on your computer)

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