WhatsApp has got a very important update. When a message is seen by the person the double tick turns into blue.
Until now now when you send a text message to a person, it shows a single tick when the message is sent from your side and when the message is delivered to that person, double tick is shown. But now when user will open and see the message, the double tick will convert into blue color.
This feature might not be welcomed by some users because of the privacy issues. But like Facebook, WhatsApp now has this functionality.
WhatsApp is the most popular instant messaging service available for multiple mobile platforms. It has over 600 million users around the world now. Facebook bought the WhatsApp for over $19 billion earlier this year but WhatsApp is operating as an independent application even since then.