Pokémate (inaccessible Japanese mobile phone app; 2006)
PokéMate is a mobile phone game developed by Square-Enix and released in 2006. The game allowed players to capture Pokémon, chat with other players, and take care of their Pokémon in a virtual pet simulator mode. New players only receive 10 Pokéballs and a random Pokémon to start. However, a "formal service edition" was released for a monthly fee of 210 yen to get more Pokéballs, Pokémates, and media within the app.
The chatroom feature allowed different players' Pokémon to sign messages between two players. This aspect of the game worked similarly to email.
The game was only released in Japan but was shown at E3 and was expected to receive a wider release in 2008. It didn't receive much attention from press in Japan or the US during its lifespan. However, the service was discontinued in Japan in 2008 and was never available in the rest of the world. Beyond a couple screenshots, there is no footage of the game available online, and there's no way to access the game since its discontinuation.