iOS too old for app? Try this.
Lately, I get more of those "iOS too old" type messages when trying to get apps using the App Store on my iPod Touch. It's an iPod 4 iOS 6.something. I'm at the very latest iOS that supports the device.
The work around seems to be to FIRST use iTunes on your computer to download the app you want thus associating it with your Apple ID. Then don't sync your iPod - instead download the app using the App Store on your iPod or iPad etc. You'll get a message saying this app is too new - do you want to download a version that works, etc. Select yes and you can load the older version of the app.