Endijuan33/app ? reverse-engineered prompt

Build me a Flutter mobile wallet app for Polkadot and other Substrate based chains. I want a clean, friendly app where people can safely manage their accounts locally, see and organize their tokens, do staking and governance actions, and sign transactions offline when needed. It should work on both iOS and Android, and it should be set up so other chains can plug in their own features later.

Please keep the experience simple and polished, with the main flows being account setup, wallet management, token viewing, transaction confirmation, scanning, and basic chain specific actions through plugins. If you need to check current Flutter or plugin docs online while building it, go ahead. Make sure the app feels production ready, uses secure local storage for private keys, and has a structure that would make it easy to add more Substrate network support over time.