Android Gym App Development

I'm looking for an experienced Android app developer to create a gym management application. The app will primarily focus on member management and will include payment processing for memberships.

Key Features:
- Member Management: Onboarding, profile management, and activity tracking.
- Payment Processing: Secure transactions for memberships.

Ideal Skills:
- Android app development
- Experience with payment gateways
- Strong UI/UX design for user-friendly navigation
- Backend development for database management

Looking for a developer with a proven track record in similar projects. Please provide portfolio and estimated timeline.