With many real-world apps, there is the need to remind the user at some point to, say, take some action or give out some information. For example, a fitness app may alert the user to begin some workout sessions.

Here, you will build on the ToDoList app from the previous chapter by setting a reminder for a task, then pop up a notification when the reminder is due. You will learn a lot as we implement these features, using classes such as IntentService, BroadcastReceiver, and  Notification. 

In this chapter, you are going to create a feature that allows the user to set reminders for tasks.

By the end of this chapter, you will have learned the following:

• To create and display notifications for the reminders set
• An introduction to push notifications
• How to use cloud services, such as Firebase and Amazon SNS, to send push notifications, and
• How to set up your app to receive and display push notifications to the user

All in all, the topics covered in this chapter include:

• Services
• Broadcast receivers
• In-app notifications
• Push notifications