Cross-Platform Messenger App Development

I'm looking for an experienced mobile app developer to create a cross-platform messenger application available on both iOS and Android. The app should primarily focus on text messaging and will incorporate advertising for monetization.

Key Requirements:
- Text messaging functionality
- Cross-platform compatibility (iOS and Android)
- Integration of advertising

Ideal Skills and Experience:
- Proven experience in developing messaging apps
- Strong knowledge of iOS and Android development
- Experience with ad integration in mobile applications
- Ability to deliver a user-friendly and secure messaging experience

Please provide samples of your previous work and a detailed plan on how you intend to execute this project.