The only extension with perfect integration for Gmail multiple accounts.

It does what it says it does unlike many other extensions and does not impede or slow browser performance down like other extensions. Makes checking, reading and managing my 2 email accounts a breeze. LOVE IT!

Excellent!

This is the perfect extension if you migrated from Google Chrome

Amazing extension! Fluid design, solid performance! Developer deserves full support!! Great work!

Thank yoy, it's greatest checker.

Es imprescindible para mí.

i have this for chrome but is there a version of this for yahoo once 57 is out

Just switched from Chrome and, after changing the button to open gmail in a new tab via the options, this works the same way as the extension I was used to using before.

thank, works great

The best Gmail Notifier. Period. Thank you for that.

Works great.

Ho provato quasi tutti i notifier di email presenti nella sezione Add-On di Firefox e Chrome, ma questo è decisamente il migliore.
Lettura, scrittura ed eliminazione delle email rapida, supporta più di un account contemporaneamente e non si blocca. Consigliato!

C'est un excellent addons. Les lenteurs que j'avais pu constater il y a quelques jours ne sont dues qu'à Gmail qui ralentit ou bloque Firefox pour nous obliger à utiliser Chrome.
Au contraire, en consultant ses mails à l'aide de Checker plus, ça reste relativement fluide, et en tous cas, ça ne bloque pas.
Cet addon serait bienvenu sur Palemoon et sur Brave

There was another review saying it doesn't automatically check for updates in FF 57, so I'm just living a review to say that it does work for me.

I've only been using this plugin a few hours in FF, but I used it for years in Chrome, so very happy to give the 5 star review.

Very useful, best addon for gmail.

Finally, found best gmail checker extension (tested on 55.0.2 64 bit)

ATM, this is the best WebExtensions Gmail checker/button. The built-in popup isn't annoying and if you really want just a button and notifier to Gmail you can just choose so.

By default this is broken in Fx57 though, because Tracking Protection enabled seems to inhibit the addon from logging in. Not sure if this is a Firefox or addon bug.

Checking it now

A lot of reviews are probably from competitors since this is the best one I've used and I've used them all.