Cake Wallet can cryptographically sign a message with your wallet's keys to prove that you control an address, and verify a message that someone else signed. It's a simple way to prove ownership of an address without moving any funds.
Open the Settings gear, tap Other, then Sign / Verify.
On the Sign Message page, type or paste the message you want to sign. For Monero, Bitcoin, Bitcoin Cash, Litecoin, and Dogecoin you can also enter a specific address to sign with; other currencies sign with the wallet's primary key. Tap Sign Message, and the signature appears in the read-only Signature field — tap it to copy.

Share the message, the signature, and (if you used one) the address with whoever needs to verify it.
Swipe to the Verify Message page. Paste in the message, the signature, and the address, then tap Verify Message.

A valid signature shows a success message; an invalid one tells you the signature isn't valid for the message given.
Hardware wallets: the Sign / Verify screen is available on hardware wallets too, and Bitcoin hardware wallets can sign — Cake Wallet passes the message to the device (Ledger, Trezor, or BitBox), which produces the signature itself. Signing is not implemented for the other hardware-wallet coins (Monero, Litecoin, Ethereum, Polygon), so use a software wallet for those. Verifying a message never needs your keys and works everywhere.

