iCloud email is the free email service from Apple with many features. With Notifier for iCloud™ addon you get:
a) Instant access to your iCloud inbox with just one click!
b) Notifies you every time you get a new email via Badge icon text.
c) Log in just once to access your mailbox anytime.
d) Change notifier's settings easily from addon's options page.
Note 1: this notifier is only for iCloud email (not other iCloud products).
Note 2: iCloud is trademark of Apple Inc. Notifier for iCloud™ addon does NOT belong or relate to the Apple Inc. at all. It is basically an unofficial addon which is developed and maintained independently by its author.