Franz is a program designed for Mac users who wish to easily manage the accounts they created for multiple chat and messaging services, such as Gmail, Facebook Messenger, Skype, etc. The application is very simple to handle, allows you to log in to various accounts from the same chat or messaging service, and displays notifications for incoming messages or emails.
Its interface is nicely designed and intuitive, with simple to configure settings. All you need to do is enter the credentials for the account you wish to manage and that's it. The program informs whenever a message or email is received. It allows you to toggle fullscreen mode if necessary, and change the default language when needed.
Furthermore, Franz uses a very small amount of CPU resources while running on your Mac. Plus, unlike Adium (a similar application which is also free), this program lets you check your emails and never fails to let you log in to the selected accounts.
In conclusion, I'd say you should definitely try Franz on your Mac if you want to quickly handle the accounts you created for services like Gmail, Skype, etc.