Very high quality, customizability, easily $10 value addon for absolutely free!

simple and quick ! the best gmail add on undoubtedly !

Très pratique, beau design... :)

Thank you. Great!

It don't adjust to the overflow menu when open an email. Please fix it.

Please add customizable shortcuts for popular actions. Thank you.

Used to be amazing and technically it still is. But there's a lot of errors lately, making this extension rather useless.
It often displays this error code:

getBGObjects@moz-extension://03031ac1-379c-4acb-aa46-59e3a7d42487/js/popup.js:436:2

Hope it'll be fixes soon, used to love Checker Plus.