You can see the Codex version your tablet is running under “Device” in the rM menu.
in addition with various improvements in the interface, enhancing feedback to the user.
in addition to various fixes and improvements.
Released on May 22nd, 2018. It mainly features improvements to the battery management.
The first major update released January 16th, 2018. See the Official Blog Post for more details on what changed:
The original release. The first reMarkable Tablets were shipped with this version.