Half bridge motor driver
The circuit looks reasonable, but it looks like the decription is wrong.
Where it says:


  The MOSFET used on the ground-side of the motor doesn’t actually need to be there. This is the brake which let you electronically stop the motor from spinning. 


It should say the MOSFET used across the motor, this would be used for the braking. This is confirmed in the truth table, where it says when N = 0 and P = 1 "MOTOR FRENADO", which means motor braking. So N is for on/off (N = 1, P = 0 is "MOTOR AVANZA" i.e motor advances) and P is for braking.