The UStream iPhone application, which lets users watch live streaming event coverage, is now available in the iTunes App store. And right on schedule: The company’s goal was to launch in time for today’s presidential inauguration.

At first, it will only operate when in range of a Wi-Fi network, according to the company, in order to ensure the best viewing quality. Like the LiveStation iPhone app announced last month, this doesn’t really make it pure mobile TV, as users are tethered to Wi-Fi. But it will soon likely be available with 3G connectivity as well.

The application so far works well and the audio and video are played relatively seamlessly (compared to many online streaming sources that are considerably bogged down today). It offers a few different streams including the one I’m currently watching from CNN (see screen shots below). These each offer the ability to chat with friends and other viewers.

See our past UStream write-up here, and get the app itself here (link opens iTunes).