Compressor is a native Android video compression application built entirely in Kotlin using Jetpack Compose and Material3 for the UI, and Android's Media3 Transformer for the actual encoding. It does not rely on FFmpeg; instead, it leverages hardware-accelerated codec APIs (H.264, H.265, AV1) to achieve fast, lightweight compression. The app follows a single-activity architecture with a ViewModel managing the full lifecycle: video selection via SAF (Storage Access Framework) or share intents, track probing to determine source properties, building a compression plan based on user-defined presets or target file size, executing the transformation, and saving the output to the gallery or a custom folder. The codebase is well-structured with clear separation between UI screens, reusable composable components (InfoRow, CheckboxRow, SelectionChip, etc.), utility classes for hardware detection and file operations, and a theme system that supports dynamic colors and Android 16 tokens. It includes comprehensive unit tests for the ViewModel, utilities, and audio processor, as well as CI/CD workflows and fastlane metadata for Play Store deployment. The project demonstrates strong Android engineering practices, with attention to edge cases (device-specific workarounds for MediaTek, Huawei, Pixel), fallback logic in audio encoding, and a customizable filename token system. While the core compression logic is tightly coupled to the app's domain, several utility modules and UI components are designed with reusability in mind and could be extracted for other Android media projects.