The main goal of packaging your classes is to simplify the navigation through your source code. This is especially important for open source applications. In my opinion, a easy-to-navigate package structure includes the following packages:
com.example.main – contains your main driver functions, such as your main activity(s), your application class (if you have one), etc
com.example.conf – contains your configuration files, such as those containing constants (static final variables)
com.example.net – network-related classes, such as those that make http requests
com.example.util – utility classes, such as services, BroadcastReceivers, or other background processes