App Bug Resolution & Android-to-iOS Conversion

I'm dealing with multiple issues with my app that need to be addressed as soon as possible. It is crashing randomly, both during startup and when performing certain actions, such as opening a specific screen, submitting a form, and playing a video. Apart from that, it's also suffering from slow performance and UX/UI issues that need immediate attention. Upon resolvement of these bugs, I need the Android version of the app converted to iOS.

Ideal Skills:
- Proficiency in both Android and iOS platforms
- Strong skills in debugging and bug fixing
- Expertise in improving app performance
- Excellent grip over UI/UX design
- Experience in porting Android apps to iOS