Parity Signer is a cold storage solution, which allows you to turn your iOS or Android device into a dedicated hardware wallet for Polkadot, Kusama, and other Substrate-based chains. Your keys are kept secure (i.e. offline) at all times, and transactions are signed in an air-gapped way via QR codes.
Using Parity Signer in conjunction with Nova Wallet means you will use 2 mobile devices to sign transactions. It is important to note that the device which has Parity Signer installed on it should be