Rush is a multi-platform (Android, iOS, Desktop) lyrics viewer and sharing application built with Kotlin Multiplatform and Jetpack Compose. It fetches lyrics from Genius and LRCLIB, stores them locally via Room, and displays both plain and synced (LRC/TTML) lyrics with per-syllable highlighting. The app features a media listener that auto-detects the currently playing song, extensive customization options (themes, fonts, backgrounds, romanization for multiple languages), and a rich share card generator with nine distinct visual themes. Architecturally, it follows a clean modular structure (core, logic, ui) with Koin dependency injection, Ktor networking, and DataStore preferences, and includes Android-specific pro features (billing, analytics via PostHog) with FOSS variants that strip those dependencies.