Chrome - For the new spell check feature in chrome, the notification is full of incorrect spellings.
Gmail - If you use a corporate mail account, when talking to a friend using the chat window, a warning appears if your chatting with someone outside of your company.
Headline Shirts - If you linger 45+ seconds on the cart checkout page you may get a discount offer that expires in 10 minutes and may deliver a coupon code for later reuse.
Tumblr for Android - pressing the “create” button for a long time lets you easily choose one of the two most frequent kind of posts (photo or text)
Facebook - The example conversation takes place between your personal user account and the page you are administering.
HipChat renders hex color swatches in-line.
Pinterest - When loading, the image containers gets the average color of it’s image.
YouTube - The favicon changes based on whether the video is buffering, playing, or paused.
Youtube - Page load progress bar in Chrome changes to Youtube red.