The simplest application is a reminder. Allows you to start events for reminders at the right time, as well as keep a list of the birthdays of your friends. Additionally, you can configure the counter days to date (how many) or from the date (how many have passed).

Drink a pill during, remind of a birthday, a reminder to feed the cat, remind the shopping list in the store. All this and much more can be customized using this application.