It looks like HTC is intent on getting all its news crammed into one week. Just a few hours before its scheduled media events in New York and London, wherein the company will reveal the New One (or at least show off whatever hasn't been leaked yet), HTC has been uploading apps to the Play Store like there's no tomorrow. In addition to the Blinkfeed launcher and SenseTV apps, the Sense versions of the Gallery and HTC Guide have been added to HTC's publisher page.
The Gallery app looks like HTC's default image browser and viewer, very much like Motorola's similar manufacturer app. It's got all the usual bells and whistles, plus a basic image recognition mode ("Image Match"), and organization by time or location. Note that the description mentions the newly-confirmed HTC One M8 Google Play Edition, specifically that it only supports the HTC Photo Edit function.
HTC Guide is a basic software manual submitted under the "books and reference" category. It has all the usual operation and troubleshooting information, plus a few diagnostic tools to help users check the health of their phones. Various tests for storage, power, connection, and more will help to check the function of your phone's hardware, after which you can contact HTC's customer support line straight from the app.
As expected, all of the new apps are compatible only with HTC phones. Keen-eyed users will notice that the screenshots use the same software navigation buttons as the New One. If all this isn't enough for you, there have been massive video and photo leaks of the new hardware.