Tezoro is a non-custodial service offering on-chain backup and will for digital assets, enabling smart contract-based recovery of crypto assets in case of access loss or the owner's death. It allows users to deploy backup contracts that transfer assets to designated addresses without Tezoro having access to the assets or mnemonic. The platform emphasizes security with CertiK audits and is open-source, supporting ERC-20 tokens across various wallets.