I need an open-source Android app (feel free to use cross-platform frameworks) that lets hobby musicians trigger samples from a grid of pads with the shortest possible touch-to-sound latency. When a user taps a pad, the assigned audio file—MP3, WAV or FLAC—must play instantly and cleanly. Pad should have two modes: one-shot and looping toggle. No additional processing such as reverb or an equalizer is required; keeping latency low is the priority. The grid itself is fully customizable: users decide how many rows and how many columns they want, then assign colors and labels to each pad. All of that, together with the file bindings and an individual volume level per pad, should be saved into named presets that can be loaded or shared later. Preset data should be stored in human readable format like XML, JSON or YAML. The finished project has to be published on F-Droid, every dependency must be FOSS-compliant. Please deliver: • a Git-hosted repository containing the full Android Studio project, • a signed release APK ready for side-loading, • F-Droid metadata (fastlane screenshots, description, build recipe). P.S. Since I need readable and maintainable code (I'm senior software developer myself), please don't misuse AI.