iPadOS 8.4.1 (build 12H321) is an official Apple over-the-air update for the iPad 4 (Global), released on 2015-08-13T18:05:09Z. The update package is 1.09 GB. This is a delta (partial) update that requires 7.1.2 already installed. This update is currently signed by Apple, so it can be applied from Settings › General › Software Update.

Payload file: cc2e06bb148dfbac03003ecd4df0477b6e2fda4e.zip.