Does this work in the background, or do you have to have that app running?

For a while I was using an iOS app called BuzzClock. I liked the feature that it would give a different # of buzzes as you went through the hour. I found this helped reduce the need to check the time when I was heads-down on some work, or give a subtle reminder that I might be lingering too long on something.

But having to keep the app in the foreground ultimately killed it for me.

I was thinking the same thing but could you imagine your phone vibrating in your pocket every 5 minutes? If I didn't expect my phone to also vibrate for phone calls and messages all day long, an app would be viable... sadly, you probably need to distinguish in an obvious way

Might be workable if you have the option to change the vibration pattern to something clearly distinct from a notification.

Agreed.

I was thinking maybe an audio queue... haha http://www.youtube.com/watch?v=OyBSrBqogPY&noredirect=1

...or attached to your hip:

http://www.fitbit.com/one

And this is a lot smaller than the bracelet.