Cross-Platform Mediator App for Data

I need a cross-platform application developed in Java, Python, C#, JavaScript, and SQL. This app will serve as a mediator interface between two government institutions. The purpose of the app is to handle data entry, processing, and analysis of personal data. The app should be compatible with Windows, Android, and iOS, using Swift for the iOS version.

Key Skills & Experience:
- Proficient in Java, Python, C#, JavaScript, and SQL
- Experience in cross-platform app development
- Familiarity with data handling, processing, and analysis
- Knowledge of personal data handling regulations
- Swift programming for iOS
- Windows and Android app development experience

Essential Functionalities:
- Data Entry: The app must provide a user-friendly interface for data input.

Please note, the application will not only be used for data entry but also for data processing and analysis. Therefore, understanding of data handling is critical for this job.