Reminders is a simple but effective app for managing your to-do list. One of its most useful features is the fact that it can notify you exactly when certain items are due using a small, unobtrusive pop-up window. This makes it easy to address the reminder or dismiss it if you don't have time.
You can also use the app to create other types of checklists, such as a shopping list, packing list, or list of family chores. Sync the app with your other devices, and you'll be able to check things off anytime.
Click the arrows to view Reminders on each device.
Reminders for Mac was introduced with OS X Mountain Lion. If you have OS X Lion or earlier, the app is part of iCal instead.
Use iCloud to sync the Reminders app. To find out if you already have it enabled, visit your device's iCloud settings. Remember, you have to configure each device separately.