[Ethereum] How to all transactions sent to an address be found

It's very easy.

1. Open the wallet and press "Send";
2. Select your wallet contract at the "From" select;
3. In the "To" field paste the address of the contract or account you want to send the Ether to.
4. Fill in an amount to send;

Ethereum doesn't discriminate between contracts and accounts, on the protocol level these are all the same so the instructions on how to send are the same as well :)

If you want to build a explore like etherscan.io, you need to crawl all data in ethereum network and save all txs in the db.

There is no direct rpc method to obtain all transactions related to the account.