The older I get, the more often I find myself awake at 3 a.m., wondering if I finished everything that needed get done the previous day and running through tasks for the day ahead. For the past few months, I’ve been relying on The Omni Group’s OmniFocus ( ) on my Macs as well as OmniFocus for iPhone ( ) to help keep my life in order and sleep a bit more soundly. The newest member of the suite, OmniFocus for iPad, complements the other OmniFocus apps, leveraging the iPad’s larger display nicely. If you’re willing to learn how OmniFocus works, it’s worth the investment in money and time.

OmniFocus lets you categorize and track to-dos like other task managers, but it also incorporates contexts, an essential component of David Allen’s Getting Things Done productivity system. Of all the concepts in OmniFocus, contexts are perhaps the most challenging ones for new users to grasp. In GTD-speak, a context is any resource that’s required for a task, whether it’s a place (the office), a tool (home Mac), or even a person (your supervisor). The idea is that by focusing on the items that are appropriate for the situation you’re in, you won’t waste time worrying about the stuff that you can’t handle at the moment.

OmniFocus makes good use of the iPad’s touch screen, changing its layout to suit the tablet’s position. In landscape mode, a sidebar on the left lets you access the Inbox, enter new items, view your projects, contexts, and perspectives (customized views), and review projects. To save space in portrait orientation, the sidebar only appears when you tap a button labeled “OmniFocus” at the top left. Overall, the interface is easy to navigate, although I found the black background a bit stark in contrast with the program’s white and gray windows.

In addition to the desktop version’s standard perspectives, OmniFocus adds a practical Forecast view that shows the number of items due for each day of the upcoming week, as well as counts of past due and future tasks. Tap on a day and a list of corresponding to-dos appears (screenshot). Unlike the Due This Week perspective, which begins on the first day of the week, Forecast starts on the current day, so you can easily see what’s on the horizon.

Thanks to the iPad’s larger screen, the Map, which shows locations that you’ve assigned to contexts, is more effective than it is on the iPhone. If you’re at the supermarket, say, you can quickly see that you have to pick up a light bulb at the hardware store on the next block without even having to remember that it’s there. (An automatic spoken announcement would be even cooler, especially in the car.)

If you run OmniFocus on more than one device, keeping them up-to-date is essential. OmniFocus supports four methods for synchronizing the desktop, iPad, and iPhone versions: directly over a wireless network, or cloud syncing via MobileMe, your own WebDAV server, or The Omni Group’s own sync server, which was still in beta as I was writing this review. My to-do lists stayed in harmony using my MobileMe account, but I sometimes had to initiate syncs manually on the iPad after entering new items.

If you’re already using OmniFocus productively, the new version is well worth $40 to manage your tasks on your iPad. But if you’re new to OmniFocus, you’ll have to put in some effort to learn its approach and use it effectively. So, before you take the plunge, I recommend that you download the free trial desktop version to see if OmniFocus is the right tool for you.

[Dr. Franklin N. Tessler is a Birmingham-based radiologist and a freelance contributor to Macworld.]