article_snippet: In December, Dutch site AndroidWorld uncovered clues about the feature while studying the app's test code.
article_snippet: the app then extracted layout files from the raw code to create mock-up screenshots (pictured).
article_snippet: Expert Sander Tuit then extracted layout files, images and text from the raw code to create a series of mock-up screenshots.
article_snippet: The Facebook-owned app displays two blue ticks in the bottom right-hand corner of an individual message to show The Facebook-owned app has been read.
article_snippet: The app's logo is pictured .