Can't download firefox browser app into iTunes library

Hi there,

I downloaded the new Firefox Browser app for my iPhone 4S and iPod 6th Generation via the App store on the devices.

I am trying to download it into my Library using iTunes but I keep getting error messages.

When try to find the app in the store it says downloading but nothing is actually downloading.

I have tried restarting my PC but I that doesn't help and I'm at a loss at what to try next.

Can anyone help?

Thanks