Flutter is a multi-platform system that allows you to write code once to output a variety of applications for iOS, Android, and the Web. Here are some insights gained from building a clone of the famous TikTok app in Flutter. I will share the information on user registration and login, uploading videos and thumbnails, uploading attached information to a cloud database, state management and screen transitions, other libraries used, and more. Some of the content is directly applicable to iOS native app development, so even those who have never touched Flutter will be able to see it.