I should rephrase my original quote, I have not been able to use the HTC app, to the point I have actually taken it off my start screen. The clock won't update correctly on the tile and I gave up on HTC's canned responses (i.e. ask Microsoft). Most major vendors know how to update their apps, HTC obviously doesn't and doesn't really seem to care, once again, my opinion.
HTC are you listening, my bet, NO!
Otherwise 8.1 has been a pleasure.