From January 24th, 2018 to March 15th, 2018, 50% user give 5-star rating, 50% user give 2-star rating. for Localhost detector chrome extension.
Works only by reading url, so no way to know if you're on localhost when using virtual hosts.
Love this one! So nice to have a big bright visual cue to distinguish local experimental development from breaking things on the live server *grin*