According to a leak reported by news website Phone Radar, Facebook will be adding a few new features to its WhatsApp instant messaging app.

The features were reported to be support for callbacks, voicemails and ZIP file attachments.

Through the callback feature, WhatsApp users on both iOS and Android devices will be able to respond to a missed call using the "Call Back" button that will be displayed in the notification of the missed call. By tapping on the button, users will no longer have to open WhatsApp to return the call that they missed.

The voicemail feature, however, will only be coming to iOS users. There is no definite information on what the feature will be able to do, but it was reported that "Record Voice Mail" and a "Send Voice Mall" buttons will be shown during a voice call. As such, it can be assumed that the voicemail feature will allow users to record and send in-call audio.

Another new feature reported to be coming to WhatsApp is the ability to send ZIP files as attachments. The app already allows users to send files in different formats such as PDF and Word documents, but being able to send ZIP files will allow users to save on their data usage. In addition to compiling multiple documents in a single file, ZIP files apply compression to the documents to reduce their size within the attachment.

There is no indication of a definite date for when the features will be coming to WhatsApp, but users can expect them to arrive soon.

Earlier in April, WhatsApp rolled out complete end-to-end encryption, which improved the security and privacy of its users. With such an encryption, it is claimed that only the sender and the receiver will be able to read messages being sent through the service. WhatsApp also said that the messages sent through the platform will be deleted from the company's servers after they have been sent.