iOS 9.3.1 (build 13E238) is an official Apple over-the-air update for the iPhone 6+, released on 2016-03-31T16:55:16Z. The update package is 1.36 GB. This is a delta (partial) update that requires 8.1.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: a8423bf8fa1799e632c7e6e41763902c3c717572.zip.