LeakCanary is an Open Source Java library to detect memory leaks in your debug builds.

Just add the dependencies in the build.gradle:

dependencies {
  debugCompile 'com.squareup.leakcanary:leakcanary-android:1.5.1'
  releaseCompile 'com.squareup.leakcanary:leakcanary-android-no-op:1.5.1'
  testCompile 'com.squareup.leakcanary:leakcanary-android-no-op:1.5.1'
}

Then in your Application class:

public class ExampleApplication extends Application {

  @Override public void onCreate() {
    super.onCreate();
    
    if (LeakCanary.isInAnalyzerProcess(this)) {
      // This process is dedicated to LeakCanary for heap analysis.
      // You should not init your app in this process.
      return;
    }

    LeakCanary.install(this);
  }
}

Now LeakCanary will automatically show a notification when an activity memory leak is detected in your debug build.

NOTE: Release code will contain no reference to LeakCanary other than the two empty classes that exist in the leakcanary-android-no-op dependency.