Mobile App UI Design with Material

I am in need of a comprehensive mobile app UI design using Material UI for both iOS and Android platforms, which should include the following features:

- User login/authentication
- In-app purchases
- Push notifications

I am looking for a skilled UI designer who has experience working with Material Design and developing mobile app interfaces. The ideal candidate should be able to create user-friendly, aesthetically pleasing designs that cater to both iOS and Android users. Experience with incorporating complex features like user authentication, in-app purchases, and push notifications is a plus.

If you think you're up for the task, please do share your portfolio and any relevant experience you have. I'm looking for a professional who can deliver high-quality work within a reasonable timeframe.