AlarmManager allows us to schedule work to run without user intervention.
This means that we can arrange to do work pre-emptively, for example, to prepare data that our application will need to present to the user when they next open the application, or to alert the user to new or updated information with notifications.
Ideal use cases include things like periodically checking for new e-mails, SMS scheduling, time notifications, periodic data processing, downloading new editions of periodical publications (for example, daily newspapers and magazines), or uploading data from the device to a cloud backup service.
The AlarmManager is able to start future work effectively but the API should be used carefully to keep your application battery power consumption at low levels. To achieve that, the developer should try to keep the alarm frequency under certain levels and use the exact set functions that force the device to wake up only in cases where it is really necessary...
