This shouldn't be in the Bitcoin forum since it is about Ether which is an Altcoin. I suggest you move it to the Altcoin discussion board.
What benefits does that site offer compared to
https://etherscan.io/ for example? You enter your ETH address and whatever is stored in your wallet is displayed as part of your portfolio.
Hi sure, etherscan shows detailed transaction of a particular address, whereas FindETH scans through your hardware (or addresses) for all addresses created using your private key (obviously your key doesn't leave your hardware you just sign it) and it will scan through addresses possible under different derivation path.
For me it's useful as I have ETH where the addresses is created using different provider (derivation path) such as MEW, Ledger Live and sometimes I worry where did I put my ETH....
And thanks for reminding me to move the thread to Altcoin!
merry christmas~