nostr:npub17tyke9lkgxd98ruyeul6wt3pj3s9uxzgp9hxu5tsenjmweue6sqq4y3mgl  or the guys at BitAxe or NerdMiner might be interested 

hardware piggy bank and signer for kids 

NOT a phone 

Connects to mum or dad’s wallet or node… very simple send, receive, check balance functionality