How Do I root Motorola x Force? I've just bought a shiny new Motorola X Force and I would like to be able to root it.

Is there an app that I can use? 

https://www.motorola.co.uk/products/moto-x-force

Any help  would be much appreceated
Good that you got the X Force instead of Droid Turbo 2 (Verizon's variant), that means your device is eligible for unlocking the bootloader and thus rooting relatively easily.


Unlock bootloader following here - all data including internal storage will be wiped, so be sure to back up.
Flash TWRP recovery here.
Flash a suitable SuperSU package in TWRP. Use "systemless" if you want to keep the system intact so you theoretically would be able to take OTA updates, or use "system mode" if you want root to persist across factory resets.
Optionally, flash CyanogenMod 12.1 here in case you're bored with Moto's UI and want it replaced altogether. You lose stuffs like Moto Assist though.