Community-Focused Chatting App Development

I am seeking a developer to create a chatting app tailored for communities and groups. This app should be accessible on both web and mobile platforms, specifically designed to foster communication within specific user groups.

Key Features:
- End-to-End Encryption: Security is a top priority. The app must ensure that all conversations remain private and secure.
- Custom Emojis: To enhance user interaction, the app should feature a range of custom emojis that can be used in chats.
- Voice and Video Calls: In addition to text-based communication, the app needs to support voice and video calls.

Ideal Skills and Experience:
- Proven experience in chat app development
- Strong understanding of end-to-end encryption
- Experience with creating custom emoji features
- Proficiency in integrating voice and video call capabilities
- Expertise in web and mobile app development

I am looking for a freelancer who is not only skilled but also understands the dynamics of community-based communication. Please provide examples of similar projects you have completed in your proposal.