This program comes as an alternative to checking your Gmail account from your default browser. The application is a Gmail client that sits on your Menu Bar and helps you immediately check new emails, compose and send messages to your co-workers or friends, and much more.
The first thing you need to do after launching this utility on your Mac is to enter you Gmail credentials. The program immediately connects you to your account and displays the Inbox panel. You can read emails, send messages, search for an old mail if needed, etc.
Also, the application gives you access to a Tips window where you can find out which global hotkeys you can use to immediately display the Inbox page or send an email. These shortcut keys can be changed in the Settings window if necessary.
Last but not least, MailPop for Gmail can display a notification whenever a new email arrives in your Inbox. The icon of the program will show the number of unread emails.
However, I think you can find better Gmail clients for your Mac. This app occasionally runs slow and displays annoying ads on its main window. MailPop PRO for Gmail, an app which is created by the same developer, doesn't bring you the aforementioned flaws and comes with a reasonable price.