I have a couple iPad 1 devices that are running iOS 5.1.1. I need to get Reader installed on them. I have installed iTunes 12.6 on my computer so I can access the app store. I downloaded Reader in iTunes. I go to the app store on the iPad and to purchased. It is there, but when I hit Install, it pops up with a message that says, "This app is incompatible with this iPad". My understanding is that it would install the latest compatible version. Has that been pulled from the app store since Nov. 2014?