Board Software
ASUS has optional software, with Armoury Crate being the central application for many casual users. In it, you can set fan profiles, RGB lighting, and download the newest drivers.
Livedash OLED
The ASUS ROG Crosshair VIII Extreme has a 2" OLED screen on the M.2 socket. It can be programmed to give different readouts or a custom animations from a GIF. Unfortunately, any saved changes will only be reapplied after a system reset when the software is re-opened.
Ai Suite 3
ASUS Ai Suite has gone through a few iterations over the years, but it still functions as overclocking-based software.
GameFirst
GameFirst is ASUS's networking tool. It allows for incoming and outgoing packet optimization. It may come in handy when streaming to Twitch or YouTube while gaming and using Discord simultaneously. A ROG-based router may be configured from within this software. I tested it out with the ASUS ZenWiFi ET8 (AXE6600) that was provided. While it isn't ROG-branded, it did show up.
RAMCache III
The RAM Cache software is useful as an extremely fast temporary drive. Just allocate how much system memory to dedicate to this virtual drive and you are off to the races; it's really that simple.