10 Must-Have Android Tools for Developers

Although Eclipse is not the only Java development environment that can be used to develop Android applications, it is by far the most popular. This is partially due to its cost (free!) but mostly due the strong integration of the Android tools with Eclipse. This integration is achieved with the Android Development Tools (ADT) plug-in for Eclipse, which can be downloaded from the Android website.

This tool serves a number of important functions. It manages the different versions of the Android SDKs (build targets) that you can develop for, as well as third-party add-ons, tools, devices drivers, and documentation. Its second function is to manage the Android Virtual Device configurations (AVDs) you use to configure emulator instances.

The Android Debug Bridge (adb) connects other tools with the emulator and devices. Besides being critical for the other tools (most especially the Eclipse ADT plug-in) to function, you can use it yourself from the command line to upload and download files, install and uninstall packages, and access many other features via the shell on the device or emulator.

The Dalvik Debug Monitor Server (DDMS), whether it's accessed through the standalone application or the Eclipse perspective with the same name, provides handy features for inspecting, debugging, and interacting with emulator and device instances. You can use DDMS to inspect running processes and threads, explore the file system, gather heap and other memory information, attach debuggers, and even take screenshots. For emulators, you can also simulate mock location data, send SMS messages, and initiate incoming phone calls.

Once you have begun to develop an app, it's important to test it on the appropriate device targets. The emulator can be used in conjunction with AVDs to simulate device targets. That said, testing on real physical devices is essential for complete test coverage. The emulator, while powerful, cannot emulate the idiosyncrasies of individual devices. Therefore, a solid test plan must incorporate both emulators and real devices. After all, your users won't be running your app on an emulator, will they?

LogCat is the name of the Android logging system. LogCat data is accessible from within Eclipse, as well as through adb, and provides helpful diagnostic information about events on the system. As a developer, you can enable your applications to log debugging and diagnostic information to LogCat as well. Logging from within an application is about as easy as a printf() statement.

The Hierarchy Viewer, whether it's access through the standalone application or the relatively new Eclipse perspective, is used to see how your layouts and screens resolve at runtime. It provides a graphical representation of the layout and view hierarchy of your application and can be used to diagnose layout problems.

When it comes to graphics design, the Draw 9-patch tool comes in handy. This tool allows you to convert traditional PNG graphic files into stretchable graphics that are more flexible and efficient for mobile development use. The tool simplifies the creation of NinePatch files in an environment that instantly displays the results.

ProGuard, which is now part of the typical Android build process, provides developers with a straightforward way to increase protection of their intellectual property after publication. The ProGuard tool can be configured to obfuscate the resulting binaries to make them difficult to reverse engineer. The ProGuard tool can also be used to optimize the size of the resulting binary, reducing the overall package size and speeding delivery to your users.