How to download apps to iphone with metro pcs carrier?

So i'm trying to help someone download apps witg metro pcs linked to their iPhone. Its unlocked but I think metro won't support apple since they don't sale the iphone. But anyways I did it along time ago I think moving my sim into the phone since i'm on a plan with att but I just don't want to repeat the hassel since I pay my bill not my friend and it uses alot of internet. Anyways I tried downloading with play store is it possible to use play store

Nope. Friend needs an iTunes account on their PC. Can download apps there then put them on iPhone. Apple uses iTunes Android uses Play Store. Can't cross. That way your friend has apps downloaded and put on the phone but not costing coin downloading directly from Metro's signal. Also, have him/her use Wi-Fi to download directly on phone and not Metro's data. Won't be a problem. Best luck.