Opmin Handler Apk Guide
It sounds like you’ve come across an named something like opmin_handler.apk (or a similar variant), and you’re seeing “interesting text” inside — possibly from a reverse engineering tool (e.g., strings , jadx , apktool , or a hex dump).

ERIH PLUS - European Reference Index for the Humanities
CEEOL - Central and Eastern European Online Library
The DOI Foundation