Signal

Signal is an encrypted messaging service for instant messaging, voice calls, and video calls. The instant messaging function includes sending text, voice notes, images, videos, and other files. Communication may be one-to-one between users or may involve group messaging up to 1000 people. Video calls can also be done in groups of up to 8 people. Signal also supports schedule sending of messages, as well as a built-in note to self feature. The android version allows changing the icon to a different style or name to not stand out to other users.

Signal
URL	https://Signal.org
Status	Unknown
Archiving status	Unknown
Archiving type	Unknown
Project source	[1] (2023) [2] (2015)
IRC channel	#archiveteam-bs (on hackint)

There is currently no way to export a chat file as easily as Facebooks WhatsApp service. Signal does support backing up to an encrypted local only file. Which can then be mirrored off phone in case something happens. However, Signal is currently working on a way to back up chats to the cloud. There are various 3rd party tools that allow for reading from an exported Signal backup to plain text or to a new device.

To export to Markdown, it is possible to follow and use Signal Export

However, Signal does support transfer of chats from 1 device to another, as per their official help pages