As time passes, manufacturers are uploading more and more system apps to the Play Store. This allows the apps to be updated independently of the device software, meaning fixes and new features can come faster instead of having to wait for the next big software update and carrier approval.
The latest app to be uploaded to the Play Store is the HTC PNS, or push notification service. This service is responsible for notifications from HTC apps, so it won’t often be used. But it’s nice to know that if any problems or vulnerabilities are found, they can be fixed quickly.