Website & Mobile App Development

Greetings!
I want to launch a new digital product that works seamlessly on the web and on iOS/Android. The scope covers the complete build of both a responsive website and companion mobile apps, with a shared back-end so data stays in sync everywhere.

A core requirement is secure user authentication on every platform. New visitors must be able to sign up, verify their email (or phone), log in, reset their password, and—if you recommend it—use social sign-in. Please include best-practice security measures such as hashed passwords and HTTPS throughout.

You’re free to propose the stack that suits the brief—whether that’s React + React Native, Flutter, or separate native apps—so long as the experience feels consistent and future maintenance stays manageable. Clean, well-commented code and concise technical documentation are non-negotiable.

Deliverables
• Fully functional website deployed to my chosen host
• iOS and Android apps accepted in their respective stores
• Admin credentials, source code, and setup/operational docs

Acceptance criteria
1. A new user can register, confirm identity, and access their account without errors.
2. Existing users can log in/out across any device and see the same data.
3. All traffic is served securely and sensitive data is stored encrypted.

Let me know your preferred technologies, estimated timeline, and any relevant live examples.