Going forward, WhatsApp users will be able delete messages from conversations and group chats up to seven minutes after they've tapped the send button, as long as both sender and receiver have updated to the latest version of the app.
The new option, called "Delete for everyone" will appear in addition to "Delete for me", and is already showing up for some users when they select a message to trash.
In a published support article, WhatsApp notes that recipients "may see your messages before it's deleted or if deletion was not successful", so the feature isn't guaranteed to work all the time. It's also possible that some users may still see the messages in notifications before they're deleted.
Users aren't notified if a delete request fails, but messages that have been successfully deleted for everyone will be replaced with "This message was deleted" in recipients' chat threads.
According to WABetaInfo, WhatsApp is currently testing group voice calls internally, so it's likely this feature will also turn up in a forthcoming update.
WhatsApp is a free download for iPhone from the App Store. [Direct Link]