SunShine is a commercial application that will unlock and s-off the bootloader on modern HTC devices (ie HTC M8).
HTC M7 is not supported at this time, likely in the future.
Price:
$25 per device
Full description and purchase:
http://theroot.ninja/
How to use with TowelRoot:
SunShine v1.1 now works with towelroot
Great to hear that it work with towelroot, but now it no longer supports the HTC One mini 2? Where is the problem?