To access the most up-to-date updates for FSX PLAY Software and FSX PLAY Courses you must visit the FSX PLAY PRODUCT SUPPORT PAGE:
FSX PLAY v1.8.3.6 and up includes an Auto-Update Notification feature within the FSX Play software that can start the update process of FSX Play for you without having to go through manually downloading and installing new builds/versions.
FSX Play has a built-in download manager that can download and install courses and notify you of any updates available for courses within the FSX Play software when they become available.