Developer Adam Outler has made one click bootloader unlock and root methods for many devices. Mostly he has worked with Samsung devices, and his bootloader unlocks and root methods have also provided the install of TWRP for the most part. These hacks have come to us in the form of CASUAL! Adam recently launched his casual-dev website which helps developers to use the open sourced java based program to deploy their own development. One of the first works of development to come from this is here. Developer "MightyBear007" has released his Recovery Flashing Tool for the HTC One. Flashing a custom recovery on the HTC One is not all that difficult, but this just makes it incredibly easy! The Recovery Flasher will flash Clock Work Mod Recovery 6.0.4.3 by developer Flyhalf205.
This will work on HTC One variants that have unlocked bootloaders. Recently the Verizon variant of the HTC One did receive an S-Off method. This will allow you to change your CID, which though I have not personally tested the theory, should also allow you to unlock your bootloader via htcdev. You can grab the CWM Flasher from the source link below.
Via XDA