What is iOS guidelines?
These guidelines describe how to design apps that follow the official HIG for iOS by Apple, not what you can do with custom controls. Sometimes it makes sense to break the rules. The purpose of this document is to guide you, not to provide solutions for complex and unique design problems.
What is design pattern in iOS?
Design Pattern Classes. Behavioral iOS design patterns identify and implement common communication patterns between objects and entities, allowing them to communicate more effectively. Creational iOS design patterns allow programmers to create new object groups safely, increasing code flexibility.