Tab Session Manager by sienori

Save and restore the state of windows and tabs. It also supports automatic saving and cloud sync.

• Save and restore windows and tabs
• Manage sessions with name and tags
• Auto save when window is closed
• Auto save at regular intervals
• Import and export sessions
• Compatibility with Chrome extension
• Cloud sync
• Support tab groups
• Import Session Buddy

Chrome version:
https://chromewebstore.google.com/detail/tab-session-manager/iaiomicjabeggjcfkbimgmglanimpnae
Edge version:
https://microsoftedge.microsoft.com/addons/detail/jkjjclfiflhpjangefhgfjhgfbhajadk

Version 7.1.0

• Added sorting by number of tabs in session sorting options
• Fixed an issue where exporting a large number of sessions fails
• Fixed an issue where keyboard shortcuts were not working

Version 7.0.0

• Migrated extension from Manifest v2 to v3
  • This ensures continued support in browsers!
• Changed the minimum interval for regularly autosave from 0.1 minutes to 0.5 minutes
  • This change is due to limitations in Manifest v3
• Fixed the behavior of tracking sessions
• Fixed the issue where windows opened outside of the tracking window were added when the "Track newly opened windows" option was enabled
  • Fixed the issue where tab groups were not saved in tracking sessions

See more release notes
https://github.com/sienori/Tab-Session-Manager/releases

I was inspired by the following great add-ons, developed as an add-on for Firefox 57 or later.
Session Manager by Michael Kraft
http://sessionmanager.mozdev.org/index.html