Rated 3 out of 5 stars
Something has changed (possibly at the Gmail end?) and now, whenever I log into my Gmail accounts via Gmail Manager I received a security warning and have to go through the two-step validation, after which I have to change my Gmail password.
This is a pain and since I have multiple gmail accounts I've been forced to change passwords almost every day.
It seems that the Gmail servers are seeing Gmail Manager as a new/suspicious device...