It’s not the new mineral found in a rare Brazilian fruit that will help you lose 20 pounds in 2 days. It’s a productivity app. And I’m a productivity nut. I’ve used every to-do app, learned GTD, zero inbox, use TextExpander for form emails, have 134 inbox rules and even converted to Dvorak so that I could type faster. In January, as a New Year’s resolution, I recorded every minute of my day to see where I could squeeze out some more time.

But Vitamin R is the best tool so far. Why? I complete things more quickly because I use it. Vitamin R keeps me focused on what I need to be doing.

It works like this. A user specifies a task, an estimated time to completion and then Vitamin R moves to the background. Every minute it chirps, reminding me that I should be working on what I set out to do. Every fifth minute, the computer speaks “10 minutes left”.

Focus is a challenge for most of us – Tweets and RSS, email, phone, SMS…. And we know that multitasking doesn’t work. Like my Catholic grade school teachers, this app keeps me on task. I catch myself switching to Sparrow after the new message notification sounds, only to hear Vitamin R’s silvery chirp nagging me back to my term sheet. And I remember that I only have 7 minutes to finish my task.

It’s changed my workflow because I’m more focused and I know precisely how much time I allocate and spend on my work. Plus when I tell my wife, “I’ll be finished in 15 minutes, I’m only 10 minutes late. Not 45.”

Give it a whirl and let me know what you think.