Downloading QuickCheck for Gmail 1.4.2 for Mac from the developer's website was possible when we last checked. We cannot confirm if there is a free download of this app available.
Please check the Mac app with an antivirus before launch as it is downloaded from the developer's website, and we cannot ensure that it is safe. The application lies within Communication Tools, more precisely E-mail. The actual developer of this software for Mac is XJH Inc.
From the developer:
QuickCheck for Gmail provides you with notifications whenever you receive new Gmail messages. The application installs in the menu bar and lets you view all your e-mails with the click of a button. The tool provides both mobile and desktop modes for viewing e-mails.
You may want to check out more software for Mac, such as MailTab Pro for Gmail, Kiwi for Gmail Lite or ToolsCrunch Mac EML to Gmail Importer, which might be similar to QuickCheck for Gmail.
Device Assistants
E-mail Tools