iPadOS 9.3.1 (build 13E238) is an official Apple over-the-air update for the iPad 4 (WiFi), released on 2016-03-31T16:52:15Z. The update package is 950.73 MB. This is a delta (partial) update that requires 8.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: b22e7ab13583401dd4c529dca9602d3ba478683a.zip.