iOS 9.3.1 (build 13E238) is an official Apple over-the-air update for the iPhone 5 (GSM), released on 2016-03-31T16:54:39Z. The update package is 282.67 MB. This is a delta (partial) update that requires 9.0.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 0f0cb5f5744c47cbc5e0d9932917a49fb7a1335f.zip.