I have a webapp for test, in this web i can do transactions with my smart contracts fro pay and change the states of this contracts.
But for confirm the transactions, i'm using metamask with a testaccount of Ethereum in the ropsten testnet. Like this example:
How i can implemantate this confirmation of transactions in mi webapp? i can do it whit web3.js or with similar API? I need the authentication of the user in the blockchain or a wallet?