iPadOS 9.3.1 (build 13E238) is an official Apple over-the-air update for the iPad 4 (WiFi), released on 2016-03-31T16:52:16Z. The update package is 347.97 MB. This is a delta (partial) update that requires 9.0.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: af3b94761c4ddab8d996361aee1c305af84a152e.zip.