Twitter is constantly tweaking its offering and tinkering with the services it provides to its users. The latest update involves the direct messages inbox. 

DM senders will be able to see when their recipient has read the message. Similar to how WhatsApp works, a small tick will appear beneath the message when it is sent and the sender can then tap on their message to see if and when the recipient has read it. 

While this is a very handy feature for those of us using DMs for work purposes, it is possible to turn it off should you wish to do so. Simply tap on settings, scroll to privacy and then untick the box next to "Send / Receive Read Receipts".