Have you tried rebooting your device? You can also try to sign out of the App Store and sign back in to see if it re-syncs up.

Thanks for the rep;y - Yes, I've tried the actions you suggest to no avail - Update: The iPhone is a 6 S rather than a 6, also I contacted Apple Support and we walked through many problem steps and concluded that it wasn't an iPhone software problem since I can successfully download and open other apps that I had 'purchased' for my iPad [just as I had done with the Firefox app as I was able to successfully download Firefox my on my iPhone 5 S] - This would lead me to suspect that there may be a problem with the current version of Firefox - I wonder if others have been successful in downloading Firefox for there 6 S iPhone

Hi lincor:

That's very strange; I have had no issues with installing Firefox for iOS on both my iPhone6S plus and my iPhone6 plus.

My guess is that you are downloading a non official version.

Are you using the official version which can be found at the following link?

https://itunes.apple.com/app/apple-store/id989804926

Cheers!

...Roland

Hi Roland - Thanks for the reply and suggestion - I followed the link you suggested and it led me to the same page I in the App Store that is giving me the trouble - That would lead me to believe that I'm dealing with an 'official' version of Firefox - As noted previously I first 'purchased' and downloaded Firefox on my iPad so when I go to the App Store with my iPhone 6 S it shows that I have already purchased Firefox on another Apple device by showing the cloud/down-arrow icon, but the icon is greyed [and therefore not active] so when I tap it nothing happens. lincor

Again very strange lincor!

Many folks have had no issue with the iPhone 6S and Firefox 1.2 (or previous versions). I have tested Firefox on iPhone 6, 6S, iPod Touch 5th generation and iPad Air 2.

I have Firefox installed on from the Canadian App Store on multiple iOS devices but I did it in the opposite order:

First I installed Firefox iOS 1.2 on my iPhone 6S Plus running iOS 9.1 Second, I installed Firefox iOS 1.2 on my iPad Air 2 running iOS (I did have to tap on "Not on this iPad" first but I don't think that is required on the iPhone).

Some questions:

1. Which iPad are you using?
2. Which version of iOS are you using on your iPad, 5S and 6S? Are all 3 running iOS 9.1?
3. Which app store are you using? Canadian? American or some other country?

Cheers!

...Roland

Hi Roland - Again, thanks for your pursuit of this - My iPad is a 'Mini 2' running IOS 9.1 - The 5S and 6S are also running 9.1 - I'm using the American App Store