@Ed, the latest version of Session Buddy (v3.4.14) is available in the Chrome Web Store:
However, Chrome should be updating the extension automatically.
If it does not, you may be running a version of Chrome that's not recent enough (Session Buddy requires Chrome 51 or later).
Note that if you decide to uninstall/reinstall Session Buddy, you need to save your local user data before uninstalling and then port it to the new installation.
See:
How to Back Up and Restore Session Buddy Data (Advanced Procedure)
Hans