Accessing Videos over NAS/Ext.HDD on Router??

[CosmoNoMAD]

Dear People!

1st: Sorry if my english is not correct... i am german.
My Question:
I have a 1TB external HDD connected to my Fritz!BOX-Router.
Is there ANY way to access this Videos with the iOS-App??
Idea behind this:
THAT way i don`t have to fire up my PC or Laptop!

It might sound silly... but; i am NO Computer-PRO. Its just... an Idea.
BTW:
The "normal" way... P.C. > Chrome-Extension > iOS-Remote works WONDERFUL!

Thx, Cosmo