Cross-Platform Utility App Development

I'm seeking an experienced developer to create a utility/tool app and accompanying website, available for sale on both Apple and Google platforms.

Key Requirements:
- Develop for both iOS and Android
- Include user login, notifications, and offline access features
- Build a responsive, user-friendly website to support the app

Ideal Skills & Experience:
- Proven track record in cross-platform app development
- Strong expertise in building secure user login systems
- Experience with push notifications and offline access functionality
- Web development skills to create a cohesive site for the app

Please provide examples of previous work and a detailed plan. Looking forward to your bids!