Tumblr iPhone app - If you swipe the edit button to the left you can create a new text blogpost. (and if you swipe it upwards you can make a photo blogpost)
/via Robin van ‘t Slot
Tehula - The slideshow demo uses names of characters from Lost.
Steam - After purchasing a game from the webstore or mobile app, it allows you to remotely install the game to the computer that you are logged into Steam with.
Foursquare iOS app - if you drag your uploaded photo to the left, you see a hidden mascot holding a camera.
Facebook Camera - After clicking the install now button, a pop-up message offers to text you a direct link to the app, with your phone number pre-filled in.
/via Taylor McKnight
Eventbrite - When using Mobile Ticket option, it automatically increases the screen brightness temporarily for easier scanning of the QR code.
/via Phil Metcalfe