Cross-Platform SaaS App Development

I'm seeking an experienced mobile app developer to create a SaaS application for both iOS and Android platforms.

Key Features:
- User Authentication
- Real-time Notifications
- In-app Purchases

Ideal Skills and Experience:
- Proven experience in SaaS app development
- Expertise in both iOS and Android platforms
- Strong background in implementing user authentication and real-time notifications
- Experience with in-app purchase systems
- Ability to create a user-friendly, intuitive interface

Looking for a developer who can deliver a high-quality, scalable app within my budget. Please share your portfolio and relevant experience.