iPadOS 9.0.1 (build 13A404) is an official Apple over-the-air update for the iPad 4 (WiFi), released on 2015-09-23T17:55:17Z. The update package is 1 GB. This is a delta (partial) update that requires 8.1.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 9671d73fbaa7784fe55f2381a2e71b33b8b316a4.zip.