The App Store just approved the updated Populi iPhone app and it's available right now.

Though anyone with a Populi user account can use it, the app is primarily aimed at students and instructors. The general idea is to give you access to the Populi stuff you'd want to see on a phone—calendars, contacts, and courses—and link it up to some of the neat stuff iPhone lets you do. For instance, you can look up your Populi contacts—and tap to make a call, send an email, or map their address. Instructors who take attendance on the iPhone get to use one of the simplest, most intuitive interfaces out there. Anything you update using the App shows up in Populi in real-time, and vice-versa.

The updated app includes support for iOS4 and the Retina Display, access to your To-Dos, and the inclusion of Lessons with your Courses. Go get it! It works on all iOS devices (iPhone, iPod Touch, and iPad). And if you want more out of your mobile Populi experience, the built-in Safari browser apps on those devices can access the whole program. What's more, our last major update introduced a new, more mobile-friendly layout that we'll be rolling out to the rest of the program in an upcoming release.