Open your Android settings. Navigate to or Privacy . Enable the toggle for "Install from unknown sources" or "Allow installation of apps from unknown sources" for your browser or file manager.
The nostalgia for God of War III is real, and the desire to play it on a phone is understandable. But the technology simply isn't there yet for a native Android version. Until Sony officially releases a port (which is highly unlikely), avoid the OBB links, protect your data, and play it on the hardware it was designed for.
If you have a PlayStation console and a PlayStation Plus Premium subscription, you can stream the God of War III Remastered edition directly to supported devices.