iPadOS 8.4 (build 12H143) is an official Apple over-the-air update for the iPad 4 (WiFi), released on 2015-06-30T15:51:11Z. The update package is 675.6 MB. This is a delta (partial) update that requires 8.0 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 4b924db96cb141ba38a089d948038aebc2a77568.zip.