AppCoins is a protocol for the App Economy supported by the Aptoide App Store, and the first ICO serving 200 million users with the goal of creating a trustworthy economy without intermediaries. The app economy has three main inefficiencies which are (1) lack of transparency or trust, (2) advertising inefficiency, (3) costly and inaccessible in-app purchases. AppCoins is the solution. It is an open and distributed protocol for app stores based on the Ethereum blockchain, using the ERC20 standard. It proposes to move the following three critical flows to the blockchain: advertising, in-app billing, and app approvals to allow transactions to occur through a blockchain-supported cryptocurrency in a decentralized, neutral and open system. AppCoins provides developers a transparent and efficient way to monetize their apps and build a reputation across app stores; provides users a trusted environment with new purchasing possibilities and incentives to discover apps; and creates an app economy with a new universal language that ensures trust, transparency, and openness.