Native apps are built in platform-specific languages - Kotlin or Java for Android, Swift for iOS - giving full access to device hardware, the best possible performance, and the most seamless OS integration. The trade-off is that separate codebases must be maintained for each platform, roughly doubling development and maintenance cost. Cross-platform apps use shared frameworks - Flutter or React Native - to write one codebase that compiles to both Android and iOS. Performance is near-native for most business use cases, development costs are 25–40% lower, and updates deploy simultaneously to both platforms. Before any app development begins, a thorough UI/UX design and wireframing process is essential - building the wrong user flows into code is expensive to undo.