Bitbucket - Chooses your default repository avatar based on your code language.
/via Joel Unger
Coda 2 - The sidebar is color-coded to show how “deep” the code is indented on each line.
/via Juan-Pablo Scaletti
Tumblr - There is an ASCII art logo in Tumblr’s HTML source.
Square card case iPhone app - Credit card form that shows card type and flips around when you get to the security code on the back.
via Matt Bilson
Read more here.