Real-Time Digital Signage Platform

I need a full digital-signage solution that can play videos, images, and text/announcements on any connected screen. My priority is the ability to push updates instantly, so the platform must refresh content in real time rather than on a schedule.

For day-to-day control, I want two management interfaces:
1. A secure, browser-based dashboard where I can upload media, arrange playlists, and monitor active screens.
2. A lightweight companion mobile app that offers the same core functions on the go.

Key deliverables:
• Front-end player that cycles through mixed media seamlessly.
• Real-time content syncing between server, web dashboard, mobile app, and each signage device.
• User-friendly dashboard and mobile UI for uploading, ordering, and activating content.
• Documentation covering setup, deployment, and how to add new screens.

If you have experience with digital signage stacks—whether that involves React, Flutter, Electron, Node.js, or similar technologies—let me know your preferred approach and how you’ll meet the real-time requirement.