How to avoid reverse engineering of an APK file?

AFAIK, there is not any trick for complete avoidance of reverse engineering. However, there are steps you can take to protect your source code, or at least what it does if not everything: 1. Use tools like ProGuard. These will obfuscate your code. 2. Move the most critical parts of the service out of the app, and into a webservice, hidden behind a server side. 3. When storing values on the device, don’t store them in a raw format. 4. Use SSL and properly validate the server certificate. 5. Insert random useless source code into your app, so that the hacker is looking for a needle in a haystack.