iPadOS 9.1 (build 13B5136) is an official Apple over-the-air update for the iPad 4 (WiFi), released on 2015-10-06T17:54:03Z. The update package is 1.17 GB. This is a delta (partial) update that requires null already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 8d6a6081620503a76675d6c20a0f2bcebf503528.zip.