You can mark a conversation as private by opening it, then tapping the 3-dot menu on the top-right, and accessing the Conversation settings or Group settings.
After a conversation is set as private, it does a few things:
- Hides the content of the message (and the sender) within the notification
- Moves that conversation to the Private conversations section of the app, outside of the main Conversation list/folders
The Private conversations section is found in the app's side menu. A fingerprint unlock, passcode unlock, or your online account credentials are required in order to access it. To set up a passcode for your private conversations, head to Settings > Advanced Features > Private Conversations Passcode.
Private conversations are a great way to secure the conversations that you don't want anyone else to look at. All of Pulse SMS's web/desktop apps also require your personal passcode to access those conversations.
The Android app will prompt you for the passcode once per minute when you try to enter the Private conversations section.