According to the lawsuit, Facebook and a number of its services including Instagram, WhatsApp and Facebook Messenger all make use of patent - protected technology created by BlackBerry, including displaying a count of unread messages on a notification bubble. (ibtimes.com)
The numbers and icons displayed on our device's screens are meant to be useful; they tell us how much battery is left, how many unread messages we have, and when we need to update something. (gizmodo.com)
displaying a count of unread messages on a notification dot. (theverge.com)