You can register and create an account in Etherscan. What can be it be used for?
As a normal user, you can add an address to the address "Watch List" and be notified by email for an incoming transfer transaction. On the other hand, if you are a developer, you can request for an API key to use with our developer services.
Please take note that Etherscan does NOT provide wallet services or have access to your private keys. Address(es) on the watch list can only used for portfolio tracking or monitoring only. To send/transfer ether or tokens from your account, you will need a compatible wallet such as Ethereum Wallet, Parity Wallet, MyEtherWallet or Metamask