Advanced Cross-Platform Content Editor

I’m building an all-in-one content editor that lets users create, edit, and preview text, images, and video from the same interface. The application must run smoothly on both desktop (Windows/macOS; think Electron, WPF, or Qt) and mobile (iOS + Android via React Native, Flutter, or native SDKs)... (Budget: ₹12500 - ₹37500 INR, Jobs: C# Programming, Flutter, PhoneGap, Qt, React Native, Unity 3D, WPF)