It works, but it erases the set up information when the browser closes. So I have to set it up over and over. The competing add on "Available Reads" keeps the information between restarts, so I don't know why this one doesn't.

One of the most useful extensions ever! Simple, accurate - and I use it on 3 libraries in my city.

Great extension, works as advertised. Very helpful to see library availability while browsing for books.

Library Extension is great. Performs as advertised... easily and quickly exposing if a book is available in my local library (Philadelphia Free Library... yeah!).

Incredibly useful with my local library, and also with Overdrive. Helps me avoid the tax-avoiding monopoly that is Amazon.

I used to do the library lookup separately. This app has saved me many hours of searching my library database to see if the books are there. And it also allows me to go directly to my library and put the book on hold. Amazing!

Great way to see if a book is in my library's collection. Love how easy it is to use.

Found out about this extension from a Book RIot article. Works flawlessly for me and my library system.

A great add-on that could be even greater if the library definitions one selects would also imply their inter-library loan systems. Colorado libraries use a system called "Prospector" that rummages through other systems in the state including university libraries, etc. If the Extension library definitions could somehow pull in the inter-library systems as well, that would make a great add-on even better! I'm pushing my luck here, but since there's an exhaustible list of libraries to choose from in the extension, perhaps a "nearest availability" option where, when a book isn't available from the chosen list then the next best/nearest availability option could be shown?

I was impressed when I learned of this extension, but when I started using it, WOW!!! I no longer use the library catalogs as this add-on gives me everything I need, faster and easier. Having cards for several libraries I used to have to search each one individually, but no more. Fantastic App! Wish it worked on mobile devices but having it on Firefox now is great!! Thanks for a Stellar product!