Although it's a multi-coin wallet, Edge wallet is a great light self-custody wallet for noobs. It has multiple purchase integrations built into it and can even help them locate Bitcoin ATMs. It's a decent security model. Your private keys are in an encrypted file secured by a passphrase. There's one copy of it on your phone and one copy stored on the Edge servers. If the user needs to restore their wallet, their username downloads the key file and their passphrase decrypts it. The app has features like biometric lock on it too, unlike most of these crappy lightning wallet apps.