Interview frequency: …
Short answer
Unify the mental model, data structure, and core tasks, while adapting controls, navigation, and interaction patterns to each platform's conventions.
Explanation
Terminology, feature scope, and user accounts should be consistent across devices so users do not feel something is missing when switching between a laptop and phone. However, iOS should follow Human Interface Guidelines, such as top toolbars and swipe-back. Android should follow Material Design, such as FAB buttons and system Back behavior. Forcing iOS design onto Android or vice versa undermines users' mental comfort.
Common mistakes
- Copying a website interface verbatim into a mobile app without considering touch-screen constraints.
- Applying one operating system's visual pattern to a competing platform (for example, using an iOS back chevron and "Back" text on Android while ignoring system Back button and gesture, or using an iOS-style Action Sheet instead of a Material Bottom Sheet).