A list of good sites where I found some nice interview resources

IOS

https://www.raywenderlich.com/2616-ios-interview-questions

https://www.edureka.co/blog/interview-questions/ios-interview-questions/

https://medium.com/@duruldalkanat/ios-interview-questions-13840247a57a

https://iosinterviewguide.com/ios-interview-questions-for-senior-developers-in-2020

FLUTTER

https://www.fullstack.cafe/blog/flutter-interview-questions

https://www.raywenderlich.com/10971345-flutter-interview-questions-and-answers

https://www.javatpoint.com/flutter-interview-questions

ANDROID

https://android.jlelse.eu/android-interview-questions-cheat-sheet-96ea01c88def

https://www.guru99.com/android-interview-questions.html

https://www.fullstack.cafe/blog/kotlin-interview-questions

Algorithms

https://www.raywenderlich.com/977854-data-structures-algorithms-in-swift

A List of Free Webservices

https://medium.com/@anoopm6/a-list-of-rest-web-services-to-try-out-for-free-63a641ba7dab