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When you've made changes to your app and want to see them in the emulator, just type the command: titanium fastdev restart-app which will quickly exit and reopen your app, using files served from the Fastdev server.
Android
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DDMS
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Device Debugging with DDMS
DDMS, or Dalvik Debug Monitor is an interface that allows monitoring of connected device or emulator logs, so you can see statements from your application as you test on a phone or emulator. If you're testing through Titanium Developer, you'll see the emulator logs already, so DDMS isn't really necessary. However, when testing on your device, DDMS is invaluable. To launch DDMS, just navigate to <android sdk>/tools in your shell, and excute ddms. This will open a window which will show a list of available devices/emulators on the left. Just select the one you want to monitor, and its logs will appear below. You can also view other information about the device and active threads in the top right of the window.
http://developer.android.com/guide/developing/debugging/ddms.html