Kotlin Explorer is a desktop application built with Compose Desktop and Swing that disassembles Kotlin source code into multiple bytecode representations: JVM bytecode (via javap), Android DEX bytecode (via dexdump), and Android OAT assembly (via oatdump on a connected device). It orchestrates the full toolchain—compiling Kotlin with kotlinc, optionally optimizing with R8, and running the compiled code—all within a GUI that provides syntax-highlighted source and disassembly views, jump arrows for branch instructions, and integrated documentation for AArch64 opcodes. The application persists user settings (SDK paths, window geometry, source code) to disk and supports macOS, Windows, and Linux. The architecture is a single desktop application with a clear separation of concerns: UI components (menus, text areas, splitters) in Kotlin Explorer.kt and related files, build/disassembly orchestration in Disassembly.kt, and parsing logic in dedicated parsers for each bytecode format (ByteCodeParser, DexDumpParser, OatDumpParser). The codebase demonstrates strong Kotlin idioms, coroutine-based concurrency, and careful integration of Swing components within Compose. It relies on external toolchains (JDK, Android SDK, Kotlin compiler) and a connected Android device for OAT disassembly. Key reusable components include a generic PeekingIterator for lookahead parsing, a thread-safe ProgressUpdater for coroutine progress reporting, a suspend helper for running external processes with cancellation, and a CodeBuilder that constructs formatted disassembly text with line numbers and instruction metadata. The test infrastructure uses a Builder abstraction that can run the real toolchain or fall back to committed test data, enabling offline testing.