Web & iOS App for Text Annotation

I'm seeking a skilled developer to create a web and iOS application that allows for the annotation of text data in various document formats such as PDFs and Word files.

Key Features:
- Annotation capabilities including highlighting, commenting and drawing/marking
- User-friendly interface suitable for easy navigation and interaction
- Flexibility
- Customization

Ideal Skills and Experience:
- Proficiency in developing web and iOS applications
- Prior experience with document annotation applications would be a significant advantage
- Strong understanding of UI/UX principles to ensure the app is user-friendly and intuitive.