Yes, ckBTC is available on mainnet:
- ckBTC minter: mqygn-kiaaa-aaaar-qaadq-cai
- ckBTC ledger: mxzaz-hqaaa-aaaar-qaada-cai
The ckBTC minter exposes a dashboard with information about UTXOs, retrieval requests, and so on.
Note that the BTC-to-ckBTC is currently restricted, so you can only transfer ckBTC and convert ckBTC back to BTC. You can follow the discussion about ckBTC here.