In ep.5 you need to find Mary, she is right near the chest with the rod (come during day or evening). Also attached save file starts near her home.
As I understood Apk and browser versions have their own saves so we can’t just add our save files for the player like we do for exe.
The saves should automatically move when you install new apk (in fact it updates the existing one), but the previous version saves will lead to malfunction now, as we keep improving the programming. Once done you’ll be able to play your saves with each new episode.