Need an instant messaging and calling app

I am looking for a skilled developer who can create an instant messaging and calling app for both iOS and Android platforms. The ideal candidate should have experience in developing apps for both platforms and be proficient in iOS and Android development languages.

Key requirements:
- Development of an instant messaging and calling app for both iOS and Android platforms
- Integration of video calling feature
- Ability to share files within the app

Additional details:
- The client already has a design for the app
- The freelancer will be responsible for implementing the design and ensuring a smooth user experience
- The client is open to suggestions and improvements to the design

Skills and experience required:
- Proficiency in iOS and Android development languages
- Experience in developing instant messaging and calling apps
- Familiarity with video calling integration
- Strong problem-solving skills
- Attention to detail and ability to deliver high-quality work on time