need some changes to my existing app

I am in need of a skilled developer who can help me make some design updates to my existing app. The app is currently available on both iOS and Android platforms, so experience with both is ideal. The changes needed are primarily focused on the app's design, rather than bug fixes or adding new features. However, new features are also a high priority for this project, so experience with implementing new features would also be valuable. The priority level for these new features is high, so I am looking for someone who can work efficiently to deliver high-quality results in a timely manner.

Add a feature in mobile app to auto update
Enable push notifications.
Social media Login
HD promotions via push and popup
Business push notification
Fast image display
Fast page load
Secure web service calls
Improve general UI/UIX
Biometric login