Improving iOS application performance is crucial for delivering a smooth user experience, as slow or unresponsive apps can negatively impact reviews and user engagement. The main thread should not be used for heavy tasks, but instead, actions like accepting user input and displaying results should be handled there. Profiling tools like Instruments can help identify performance issues and optimize code. Monitoring application behavior with Sentry is essential to track errors, performance issues, and latency. Reducing view hierarchy, frequency of operations, decoding images, handling app in background, scaling images, optimized operations, setting background efficiently, improving app launch time, caching, reusing identifiers, and being aware of memory warnings are all important factors to consider. Additionally, displaying shadows efficiently, managing legacy projects with storyboards, and using Sentry's trends view can also improve performance. By following these tips, developers can supercharge their performance improvement journey and create high-performance iOS applications.