Sarutobi Island is a blockchain-integrated mobile game developed by Christian Moss (
@MandelDuck), released on the iOS App Store on August 26, 2017. It’s a spin-off from the original SaruTobi game, which debuted on December 19, 2014, as one of the earliest play-to-earn titles where players could earn small amounts of Bitcoin while playing.
The game’s concept evolved from discussions with developer Koji Higashi, focusing on using NFTs (then called “tokens”) to generate in-game elements. By 2025, Sarutobi Island made a comeback to the App Store after a hiatus, becoming the first iOS game approved for real Bitcoin microtransactions via the ZBD payment system and Bitcoin’s Lightning Network. This allows players to earn and spend “sats” (satoshis, the smallest Bitcoin unit) on in-app purchases or cash out directly - a major milestone in crypto mobile gaming.
Built on Counterparty, SaruTobi Island continued to pioneer NFT use in gaming, and heavily integrated with Spells of Genesis (SoG) by EverdreamSoft.
SoG cards like SARUTOBICARD, SATOSHICARD, and CNPCARD were made playable in SaruTobi starting June 2016— marking the first interoperability between independent games.
Later, ZAIFCARD and ETHEREUMCARD (also SoG Cards) had promotional crossovers. Rare Pepe assets (e.g., SARUTOBIPEPE) also unlocked special skins, blending meme culture with gaming.