Summarize findings, prioritize user safety: prefer official channels; treat unofficial “Halloween Edition” APKs as high risk unless provenance and integrity can be verified.
The content from the Halloween update was integrated directly into the standard mobile port during its major remaster. How to Get the Halloween Content on Android Fnaf 4 Halloween Edition Download Android
is the only legitimate version for Android. Although it lacks the standalone "Halloween Edition" features, it does include some content from that update: Nightmare Balloon Boy prioritize user safety: prefer official channels