Cannot add Purify to my Fourth Gen Ipad

[iMore Question]

I have read all the reviews of Purify Ad Blocker and have tried numerous times to download it from the App Store. I keep getting a message that the app s not compatible with my device. In my settings app, I don't have a section under Safari that allows ad blockers. I am running IOS 9.1. Can you help, please?

 

[Just_Me_D]

The app is compatible with the list of devices listed in the screenshot.