For a pure, kinetic novel experience, 'Sound of Drop - fall into poison -' is a horror VN on Android with full Japanese voice acting. The CGs are creepy and effective, centered around a cursed aquarium. The voice acting adds immensely to the sense of panic and mystery as the protagonist investigates. It's a paid app with no in-game purchases, so you get the complete story.
The sound design, combined with the voices, creates a genuinely unsettling atmosphere. It's a shorter, focused horror tale rather than a 50-hour epic, which can be perfect for mobile play. If you enjoy voiced horror where the audio is a key component of the scare, this is a solid pick. The art style is distinctive and the character voices are emotionally charged.