HTC, while announcing the HTC M8 announced that it would be bringing a vast majority of the Sense UI elements to the Google Play Store so that the users would be able to update the apps as and when new features are available instead of having to wait for major Android updates from the OEM. This meant several system apps such as HTC Input, BlinkFeed etc were made available directly for download in the Google Play Store.
The latest app to join the list is the HTC Clock app. The app is now available directly from the Play Store so that users will be able to update the clock on their HTC supported devices as and when a new feature is added. This is a move that perhaps coincides with the rumored Android 4.4.3 update that the M8 users are receiving across the world. Needless to say that the application will be incompatible with just about every single other smartphone than the HTC M8 at this stage. We tried to update or install the app via Google Play on our M8, but the app showed that it was incompatible.
The only sense out of this is that the app will spring to action when an update is available. For now though, there are no updates for the app. But, we did receive an update to the HTC Service Pack which perhaps will prepare your device for the upcoming updates.