As I mentioned previously there's a few additional installation steps for developing mobile apps.
Although Titanium enables you to create software for iOS, Android, Blackberry and ether mobile platforms, you'll also need the associated development environments to build native apps.
If it's Apple's iPhone and iPad devices you're interested in then you will need an Apple Mac. This is because Apple's Xcode development environment is used by the Titanium toolset to build native iOS apps.
Apps for Google's Android platform are built using the Java-based Android development kit, So, this needs to be installed on your PC first. However, this time it's a cross-platform SDK, meaning you can use a Windows, Linux or OS X.
In a similar way building Blackberry apps requires another SDK installation. Once again it's a cross-platform kit for Windows, Linux or OS X.
Titanium's tight bindings to these platform-specific SDKs extends to the selection of specific OS profiles (or versions). This is important as not all users of your app will have the latest and greatest iOS, Android or Blackberry OS version.