Dual-Screen Account Control

I need an app that lets a single user session stay active on two devices or two separate screens at the same time, with every action mirrored instantly between them. Think of it as logging into one account, then being able to work from two viewpoints in parallel without either screen forcing the other to log out.

Scope of work
The build must run smoothly on both iOS and Android, so a shared-code approach such as Flutter or React Native makes sense, but I’m open to whatever framework you are most confident will hit the performance target. Authentication is a straightforward email-and-password flow; no social or biometric options are necessary. The interface should stay simple and minimalistic—clean lines, uncluttered navigation, and nothing more than the fields, buttons, and indicators required for the dual-screen workflow.

Key requirements
• One account, two simultaneous active screens
• Real-time sync of actions between screens (no noticeable lag)
• Automatic session recovery if one screen temporarily disconnects
• Secure backend handling for credentials and data in transit
• Clear documentation so I can hand the build to another developer or my in-house team later

Deliverables
1. Production-ready iOS and Android builds
2. Complete, well-commented source code
3. Brief setup guide for the backend or any third-party services used
4. Short user guide that explains how to initiate and manage the two-screen mode

Acceptance criteria
The job is finished when I can install both apps, log in with the same email/password on two devices simultaneously, interact from either side, and see updates mirrored instantly without either device being forced out.

If you have tackled real-time sync or multi-device session problems before, tell me what you shipped and how you solved latency and conflict issues.