"Checker Plus for Gmail" has gone from excellent to completely useless overnight! This extension worked well until a few weeks ago when the wheels came off:

I can no longer add gmail accounts! I have 3 accounts. There is a very weird "option" in the "Preferences" tab: "AUTO DETECT" or "ADD ACCOUNTS". I never had trouble with this in the past, but now if I select "AUTO DETECT" I cannot add an account, and if I select "ADD ACCOUNTS" I get an error message from "Checker Plus" when I try to add!

No idea what's causing this, but "Checker Plus" has now been relegated to the ranks of "NOT READY FOR PRIME TIME".