PopTrayU - Have you fallen in love with the fabulous email notifier program Poptray, but you're running a...

CatLight - Shows build status in your tray

Checker Plus for Gmail - Displays new emails and the sender's contact photo, get notifications or even listen, read or...

Tempomat - Continuous monitor integration monitor for macOS, sits right on the menu bar.

Gmail Notifier (restartless) - is a highly customizable browser extension that notifies you about the incoming emails from all your Google-Mail accounts and labels. Gmail notifier is available for Firefox, Chrome, Opera and Safari.

WhatsON - Free and open-source build status monitoring for Windows with support for Jenkins, Travis-CI, CC.NET. Designed to notify developers or other collaborators about issues in the build pipelines.