While "mff-0.5.apk" is not a standard release, the acronym "MFF" is commonly associated with:
: If this file was found on a forum or a third-party site, check for user reviews or developer notes explaining its purpose. File: mff-0.5.apk ...
: A popular action-RPG by Netmarble. Official versions are much higher than 0.5, suggesting this file might be an unofficial mod, an extremely old version, or a fake installer. While "mff-0
: A personal training and workout tracking app available on the Google Play Store. an extremely old version