Creating applications for iOS systems typically involves the following steps:

1. Set Up Development Environment: You need a Mac computer running macOS and Xcode, Apple’s integrated development environment (IDE) for macOS. 

2. Learn Swift Programming Language: Swift is the programming language used for iOS app development. You should familiarize yourself with Swift syntax, data types, control flow, and object-oriented principles.

3. Understand iOS App Architecture: Learn about the Model-View-Controller (MVC) architecture pattern commonly used in iOS development. Understand how data, presentation, and user interaction are separated within an iOS app.

4. Design User Interface: Use Interface Builder in Xcode or write UI code programmatically to design the user interface of your app. Understand Auto Layout for creating responsive interfaces that adapt to different screen sizes.

5. Implement App Logic: Write code to implement the functionality of your app. This involves handling user input, processing data, interacting with APIs, and managing app state.

6. Test Your App: Use Xcode’s built-in tools for testing your app on simulators or real iOS devices. Perform unit tests, integration tests, and UI tests to ensure your app functions correctly and is free of bugs.

7. Optimize Performance: Identify and optimize performance bottlenecks in your app to ensure smooth user experience. This may involve optimizing algorithms, reducing memory usage, and improving loading times.

8. Submit to the App Store: Once your app is ready, submit it to the App Store for distribution to iOS users. Follow Apple’s guidelines for app submission and ensure your app meets all requirements.

As for managing the lifecycle of a mobile app, here are some key aspects to consider:

1. Development Phase: This is where you design, develop, and test your app. It involves planning, coding, debugging, and iterating until your app meets the desired standards.

2. Launch: Once your app is ready, you launch it on the App Store. This involves creating promotional materials, setting up marketing campaigns, and generating buzz to attract users.

3. User Acquisition: After launch, focus on acquiring users for your app. This may involve app store optimization (ASO), social media marketing, paid advertising, and other user acquisition strategies.

4. User Engagement: Engage with your users to keep them interested in your app. Provide regular updates with new features, bug fixes, and improvements based on user feedback.

5. Retention and Monetization: Retain users by providing value and offering incentives to keep them coming back. Implement monetization strategies such as in-app purchases, subscriptions, or ads to generate revenue from your app.

6. Support and Maintenance: Continuously support and maintain your app by fixing bugs, addressing user concerns, and keeping up with platform updates. Regularly update your app to ensure compatibility with new iOS versions and devices.

7. Sunset: Eventually, you may decide to sunset your app if it becomes obsolete or no longer viable. Properly communicate with your users and provide alternatives if necessary.

Throughout the lifecycle of your app, gather data and analytics to monitor its performance, user engagement, and revenue generation. Use this data to make informed decisions and optimize your app for success.