Time Lines
Simple Apple/iOS-oriented app that visually shows you "when" your contacts are. Handy at-a-glance view of how available people (and I guess resources) are across timezones.
From what I've been able to see on the Net, this is the tweet that first suggested using a hash and a symbolic name to group together tweets by subject.
I can remember, back in the day, using this and an external website to then search particular tags on Twitter. Sadly I forget the name of the website.
An article exploring, in some part, the idea that science works as well as it does because failure is a feature and is (or should be) embraced.
I wish software development would do this more too.