As the information is coming from HTC’s UK office, the August time-frame should only be considered accurate for the region, but that doesn’t mean other markets won’t get the update around the same time. It is quite likely that One M8 update in most markets will arrive before or soon after the UK release.
The company has not shared any change-log at this point, but as we already know Android 5.1 mainly brings security fixes, performance enhancements, and HD voice support. HTC Sense 7, on the other hand, includes a new theme app, brand-new home-screen widget and enhanced version of Blinkfeed. You can read more about Sense 7 here.
