It is A transaction checker that assist your transactions and help avoiding scams.
Sign Assist helps you avoid scams & phising in Web3.
When you make a transaction it shows the end result before-hand.
Common scams like wallet drainers, phishes, impostor sites, approval scams etc are all detected.
You don't need to change your wallet. Sign Assist works alongside existing wallets like Metamask & others
Sign Assist works by reading the transactions that a dapp is making to your wallet. It doesn't have the power to change or control your txns.