At the time of this writing, the iPhone is available in more than 90 different countries, and that number will continue to increase over time. You can now buy and use an iPhone on every continent except Antarctica. The iPad was held back a bit, as Apple struggled to satisfy demand in what it considered the most important countries first, but now the iPad is also sold all over the world and is nearly as ubiquitous as the iPhone.
If you plan on releasing applications through the App Store, your potential market is considerably larger than just people in your own country who speak your own language. Fortunately, iOS has a robust localization architecture that lets you easily translate your application (or have ...