Signal

 Signal suddenly started popping up so I investigated.

Signal is a free, highly secure messaging app known for its strict focus on user privacy. It uses end-to-end encryption, meaning only you and the recipient can read your messages. It supports texts, voice and video calls, and group chats.

Getting started is as simple as downloading a standard texting app:

Download the app: Go to your mobile device's app store (the Apple App Store for iOS or the Google Play Store for Android) and search for "Signal." 

Open and register: 

Launch the app and enter your phone number to create an account.

Verify: You will receive a verification code via SMS or an automated call. Enter this code to confirm your number.

Set up your profile: Add your name (it does not have to be your real name) and an optional photo.

Signal will automatically scan your contacts to see who is already using the app so you can start chatting securely.