Nexscard?

Hello i just found out about this. Im guessing its legit? Not only you get paid early but its a debit card as well? So im guessing if i did this then it will probable replace my navy fed as in it was exactly the same? Also if i did make the switch would i make it before the pay cut? And if i dont im guessing itll just go to my navy fed<? Sorry yall please let me know any advice thank you!!