For those who have their JNCIA (or higher), what materials/video lectures/labs etc. did you use to study?

I am soon transitioning from a Hosted PBX Repair position into a NOC role and was advised by my new manager that most of the gear I will be using in my day to day is Juniper hardware, and that getting any related certs wouldn't hurt.

My current position has exposed me to MX, SRX, and QFX Enterprise routers and EX switches, so I'm not walking into my studies blind, but I do not believe myself to be test ready.

I have the Junos Genius app which is decent, but is limited to mobile/tablet. I read up on the course Udemy offers and that seems promising as well. But I figured it wouldn't hurt the guru's here if you have any advice. Any and all help is welcome!