Just as Google has done with its system apps, HTC is placing more of its core apps in the Play Store so that users can download and update them directly. The HTC Clock went live in the Play Store Wednesday, joining the Sense keyboard, BlinkFeed, HTC Gallery, Sense TV remote and other Sense apps.
By making their core apps available in Google Play, HTC can send out bug fixes or feature enhancements and they'll arrive in user hands much faster than they would if they were sent out via an Over The Air (OTA) update sent directly from the wireless carriers. These updates tend to get bogged down in a laborious approval process and take a long time to actually hit devices.
Despite these Sense apps’ presence in Google Play, only people with approved HTC devices can download them to their phones. While the Play Store page for these apps does not specify which models of HTC devices are eligible, presumably flagships such as the One M8 and One Max would qualify.