Wavebox, Mimestream, Kiwi for Gmail, nPOPuk, Magic Mail Monitor (MMM), PopTray, Gmail Unread Counter (Widget), PopTrayU, PopMan, POP Peeper, Mia for Gmail, Mailplane, Mail Notification, Gmail Watcher, Gmail Peeper, Gmail Offline, GmailAssistant, MailTab for Gmail, Gmail Notifr, MailBar, NoteSync with Google Docs are some alternatives to GMDesk.