iPadOS 8.4 (build 12H143) is an official Apple over-the-air update for the iPad mini 2 (Cellular), released on 2015-06-30T15:51:14Z. The update package is 423.1 MB. 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: 1839733072766ec507d79559677ee2ebeeb56bcb.zip.