There isn't currently a wallet for iOS using the secure enclave. But the tz3 accounts use p-256 encryption and were put in primarily to support iOS, Android, and other devices which are only compatible with p-256. There has been some work toward multisig contracts intended for use with secure enclave based wallets, I would expect we will see something soon.
The main challenge is that unlike a hardware wallet device such as Ledger, the secure enclave does not allow the importing/restoring of a key. The keys are created internally and never leave the enclave so there is no export. This makes backup/restore challenging in the case of a lost device. The most common solution will be a multisig where the enclave based key is only 1 of x.
This is how Apple describes the secure enclave:
The benefits of the Secure Enclave are balanced against a few restrictions. In particular, the Secure Enclave:
Is a hardware feature of the Apple A7 or later A-series processor. Only iOS devices with one of these processors or a MacBook Pro with the Touch Bar and Touch ID support this feature.
Stores only 256-bit elliptic curve private keys. These keys can only be used for creating and verifying cryptographic signatures, or for elliptic curve Diffie-Hellman key exchange (and by extension, symmetric encryption).
Can’t import preexisting keys. You must create keys directly inside the Secure Enclave. Not having a mechanism to transfer key data into or out of the Secure Enclave is fundamental to its security.