Does your application need to connect to a server and download data to keep its content fresh? Does the data come in at random times, as opposed to on a schedule (such as a once-a-day news article download)? Are you considering implementing a polling mechanism so that your Android application can routinely check your application server for new content? If this is the case, you might want to look into the Google Cloud Messaging for Android (usually referred to as GCM) service instead, because it can save you a lot of work and results in more efficient use of the user’s device resources. In this chapter, we talk about this Google-provided third-party service, which is available to Android developers.