iPadOS 8.4 (build 12H143) is an official Apple over-the-air update for the iPad 4 (Global), released on 2015-06-30T15:51:12Z. The update package is 319.2 MB. This is a delta (partial) update that requires 8.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 0ecdddfee3ad3578d05fc68b4dc29893ed4d2a77.zip.