WhatsApp said the secret code feature is beginning to roll out, and will be available globally in the coming months. The privacy option's launch follows other updates in the texting space this month.

A SPECIAL code hidden inside of your text conversations reveals if someone is spying on you. You can check this secret code at any time to expose a sinister kind of “text interception”.… ...

A small but inconvenient change in Google Messages will add an extra step for dual-SIM users who want to swap lines while texting.