I need an end-to-end slot-booking solution that works seamlessly on iOS, Android, and any modern web browser. The goal is to let people find an available playground, lock in a time, and manage any last-minute changes without headaches—while giving venue owners and my own admins the control they need behind the scenes. Core booking flow • Real-time availability must refresh instantly so double-bookings are impossible. • Users should be able to set up one-off or recurring reservations, then cancel and receive refunds according to configurable rules. • Integration Payment option Role-based access • Standard users book and pay. • Playground managers confirm, block out, or adjust slots. • An admin panel lets me oversee the entire ecosystem, tweak policies, and pull reports. Tech expectations I’m open on the exact stack, but the final product must ship as native mobile apps (App Store & Google Play) and a responsive web app sharing the same back-end. If you prefer Flutter, React Native, or a similar cross-platform framework, mention it; just make sure the web front end feels first-class, not an afterthought. Real-time data can run through Firebase, Supabase, or another real-time database layer as long as latency stays low. Deliverables 1. Source code for mobile and web. 2. Deployed staging environment for live testing of real-time booking logic. 3. Production deployment hand-off with documentation covering build steps, environment variables, and role-based access controls. Please outline your proposed tech stack, any similar booking systems you’ve shipped, and a realistic timeline to reach MVP and full release.