The Twitter for Android app was developed jointly between Twitter and the Android team as a perfect example of the way a third-party developer can integrate their application seamlessly into the Android experience. Covered in the posting are various elements and the thought processes behind their implementation, such as contact sync and QuickContact access, search, and widget development.
The info doesn’t get too technical, but it offers an example of one of the best-integrated apps to hit the Android Market in recent months and exactly why it fits that bill. I’m not the overly tech-savvy type, so I won’t even try to offer some paraphrased retelling, but if you have any interest in how to go about making awesome apps, I’d head on over and read up on what the Android Developers have to say.