We have an existing All-in-One Games App source code and need an experienced developer (or team) to modernize the design, add new features, and migrate the backend from Firebase to our own hosting. Tasks & Deliverables: 1. Modernize the UI/UX design. 2. Add offline HTML5 game support. 3. Migrate backend and admin panel from Firebase to custom hosting. 4. Optimize app performance and fix any existing bugs.