Mobile messaging service WhatsApp has reportedly come up with a new " double blue tick" feature that allows users to know when their texts have been delivered and read.

The blue tick appears as soon as the person at the receiving end has read the message.

According to Daily Express, one grey tick means a message has been successfully sent, two grey ticks show it has been delivered and a blue tick means the message has been read.

The app now also shows the exact time a text was sent. Users need to press and hold down on a particular post to know the accurate time the message was sent to them.

The changes will affect all versions of the app used on the Apple iPhone's iOS, the Android operating system, as well as Windows phones, Nokias and Blackberrys, the report said.