Smart contracts on Ethereum are fully self contained and any information or access to off-chain data is restricted. Tellor solves this problem by creating a system where parties can request the value of an off-chain data point (e.g. ETH/USD) and miners compete to add this value to an on-chain data bank, accessible by all Ethereum smart contracts. Inputs to a data series are secured by a network of staked miners. The main Tellor smart contract creates a time series of each requested data series and aims to become the standard source of high value data for decentralized applications. This oracle, “Tellor”, utilizes similar incentive mechanisms to other cryptocurrency systems through the issuance of Tellor’s token, Tributes, that are used to request a particular data series from miners.
Spendcoin is a decentralized cryptocurrency that powers the Spend.com ecosystem of products. Spend has two financial services products, the Spend App and Spend Card, which are products of Spend.com that give our users a multi-currency digital wallet that they are able to store fiat and digital assets/currencies. They will be able to buy, sell, store, manage, and exchange all supported currencies within the app. The Spend App is available on iOS, Android, or Web based devices. The Spend prepaid debit card allows users to send fiat based currencies loaded onto it via the Spend App anywhere that accepts MasterCard. Spend Foundation is also launching a decentralized educational platform called Blockchain University (bu.org). Blockchain University is designed to run off our open-source blockchain called Cross Ledger which incorporates a hybrid delegated proof-of-stake consensus model called Proof-of-Support. Proof-of-Support creates a learning based ecosystem that rewards those users who support and answer the knowledge base and Quora style system. Spendcoin will be the native digital currency powering the platform. Blockchain University and Cross Ledger are planned to launch in 2019.