10. DDMS

The icing on the developers' cake - we are spoilt rotten by this awesome tool.

Never before in the field of mobile development have you been able to control your device with such power. DDMS stands for Dalvik Debug Monitor Server and is the interactive tool which ships with the SDK. Veteran mobile developers will tell you that the biggest problem with handset development is knowing what the device is doing at any moment. Emulators can go so far but often don't cut the mustard when it comes to behaving exactly as if it's a real world device. DDMS talks to both the emulator and the real hardware. All Android devices have support for a comms system called the ADB, short for Android Debugging Bridge. When you run up the DDMS you get a visual representation in your IDE of what the code in the connected system (emulator / hardware / both) is doing via the ADB, and you can interact with it.

The DDMS is documented here, and here's what it's like in action:

The great thing about the DDMS is that it really doesn't know if it's dealing with a physical device or the software emulator - and that's exactly what you want because neither does your code. As you can see above, you can monitor the processes, data storage (push and pull files to and from its sdcard for example) but the best feature is the LogCat, this is the system which lets you filter logging code in the Log window, explained in more detail here.

Your IDE will most likely already have a regular debug window where you can set breakpoints and single step code, but that's aimed at any regular Java process. The DDMS understands specifically your Android device, so is really worth getting to know well when you need the extra level of control it offers.