Our journey is over! It's been quite a rollercoaster, from the history of the operating system to how it can equip devices ready to communicate with the external world. You learned how to retrieve the source code for your devices, how to navigate the source folder tree, and how to create the perfect setup to properly build a vanilla Android system.

You stepped up and started to add customizations to your system, to enrich the user experience, to improve the performance, and to add support for your own hardware. You went deep into the boot sequence's inner structure to customize the system even more. You swam back to the surface to customize the highest part of the architecture pyramid, the user interface, to provide your users with the ultimate customized Android system.

Finally, you saw how easy it is to step away from the Android device itself and find a whole world of devices waiting to communicate and interact, powered by the awesome Android platform.

Our journey is over, but your own has just started! Master what you learned, experiment, try out your ideas, fail, learn more, try again, and finally succeed!

Android is an awesome tool; you can use it to make your craziest ideas become a reality!