MetaMask (web/mobile) - helps you to handle your Ethereum wallets. Should be installed:
https://metamask.io/
Contract Address in Ropsten Testnet Network:
https://ropsten.etherscan.io/address/0x6b304e591bfb132d2c9a11e4F016270767200CFD
Contract Address in Real Network:
https://etherscan.io/address/0x43A96962254855F16b925556f9e97BE436A43448
Stack: React, web3.