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.
Roobee describes itself as a blockchain-based investment platform that allows people to make investments starting from $10. Roobee uses AI and blockchain to provide its users with transparent records and personalized investment product choices. Roobee blockchain infrastructure is powered by Ethereum blockchain and Roobeechain - a permissioned blockchain based on HyperLedger, with the goal of providing users with data privacy without compromising transparency and security. More information can be found at (https://roobee.io)