Find My iPhone - When your iOS device has been located, it shows the remaining battery level, so you know if you’re going to lose track of it soon.
iOS 6 - When turning the volume up with headphones connected, the volume bar shows warning indicators in yellow and red.
/ via frietman
Google Flight Search Results - On mobile, Google flight status results include an airplane placed on a line at a point relative to its flight progress. Color communicates whether the flight is on time or not.
/via Erin Olmon
Boxee - When not connected to the Internet, the Boxee logo goes orange and starts sleeping.
/via Emil Tullstedt
Google+ - When searching, the page indicator arrow slides from the left side to the top.
/via Vedran Židanik
Chrome - Update indicator turns brownish color (originally green) when its been neglected for a long time. Reminiscent of fruit going bad.
Cornerstone - The number of segments in the spinning activity indicator equals to the number of running activities.
/via Yusuf Miles
Basecamp - Speech bubble is green if the item contains unread comments.
/vis Shaun C.