My buddy Louis, aka Keeper, let me know about his latest creation ESX. ESX is his Engineering Screen Unlock Code Generator that unlocks the engineering screen on BlackBerry 10 devices and older BlackBerrys. All this app does is generate the hidden code just like the online generators that we mentioned in our Engineering Screen (EScreen) guide. You simply use this app instead of those websites to be able to have the generator locally.
You can download the ESX Engineering Screen Unlock Code Generator BAR here for free but you have to sideload it to your device. You can then follow the instructions in our guide for unlocking the engineering screen on BlackBerry 10. Once again kudos to @Louis_Keeper for the free app!