iOS 8.4 (build 12H143) is an official Apple over-the-air update for the iPhone 4s, released on 2015-06-30T15:51:17Z. The update package is 341.61 MB. This is a delta (partial) update that requires 8.0.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: f86d74f2204ea31eb9a22d7ba3da30102fba1495.zip.