Summary.java

package com.android.dex;

import java.io.File;
import java.io.IOException;
import java.util.Map;
import java.util.TreeMap;
import java.util.concurrent.atomic.AtomicInteger;

public class Summary {
  public static void main(String[] args) throws IOException {
    Dex dex = new Dex(new File(args[0]));
    Map<String, AtomicInteger> packageToCount = new TreeMap<String, AtomicInteger>();
    for (MethodId methodId : dex.methodIds()) {
      String typeName = dex.typeNames().get(methodId.getDeclaringClassIndex());
      String packageName = typeNameToPackageName(typeName);
      AtomicInteger count = packageToCount.get(packageName);
      if (count == null) {
        count = new AtomicInteger();
        packageToCount.put(packageName, count);
      }
      count.incrementAndGet();
    }
    for (Map.Entry<String, AtomicInteger> entry : packageToCount.entrySet()) {
      System.out.printf("% 8d %s%n", entry.getValue().get(), entry.getKey());
    }
  }

  private static String typeNameToPackageName(String typeName) {
    if (typeName.startsWith("[")) typeName = typeName.substring(1); // arrays
    if (!typeName.contains("/")) return "<default>"; // default package
    return typeName.substring(1, typeName.lastIndexOf('/')).replaceAll("/", ".");
  }
}

You'll need dx.jar on your classpath.

There is no Dex class in dx.jar.

I'm not seeing Dex in dx.jar either. My dx.jar is from $ANDROID_HOME/build-tools/18.0.1/lib/ @swankjesse you sure its in dx.jar?

Thanks for this code, works pretty well.