This is quite a neat effect that you can add to any of your views on your app. Essentially as you move your phone, the accelerometers inside predict the orientation changes of the phone and provide this movement to your view. It is a great trick to help bring attention to prominent views or images in your app.
It is an essential part of software development to handle errors correctly and iOS development is no different. It is important to reduce the impact of the error to your user and inform your user clearly if an action is required.
iOS Sharesheets are a great way to allow your users to share content from your app. This is a great way to provide your users with the ability to share your app with their network of friends and family for you. A recommendation from somebody you trust is both more powerful than an advertisement and free for the app owner. It is also very easy to do.