Nippon Ichi Software has released Kuon no Kizuna: Sairinshou, a visual novel originally released for Dreamcast in 2000 followed by PS2 in 2002, for iOS via the App Store and Android via Google Play in Japan.
Kuon no Kizuna: Sairinshou is based on Kuon no Kizuna, a love adventure game released by Fog (now owned by Nippon Ichi Software) for the original PlayStation in 1998, but adds new scenarios. The smartphone version further adds high-resolution illustrations and a “Viewing Mode” that lets you enjoy specific scenes and background music.
Here’s an overview of the story, via VNDB:
This story starts out from the perspective of a high school student. One day a transfer student comes to his school, and tells him she’ll kill him. At the same time, he starts seeing weird dreams and people mysteriously gets killed in his city.
Soon he realizes that them two are incarnated personalities of a man and a goddess that fell in love 1000 years ago. Since then, they have been trapped in a cycle of reincarnation and a battle against an evil god.