Nexo Player
A premium Android media app that turns local files into a private, AI-powered playback experience — local video and audio, audiobook generation from documents, offline AI narrators, secure vault, and Chromecast.
Role
Product engineer & system architect
Stage
completed
Scope
End-to-end product
About the product
The challenge
Most media players treat the phone as a dumb file browser. Users who keep media on-device also want to turn documents into audiobooks, lock private files, and listen offline without signing into cloud services.
The approach
Nexo Player is built around a local-first, privacy-first architecture: native Android media playback, on-device document parsing, offline AI text-to-speech, biometric-secured vault, and Chromecast output — all in one app.
Outcome
A single, premium Android product that replaces multiple apps: local player, audiobook studio, secure gallery, and podcast-style listener.
Capabilities
Video Player
Gesture controls, Picture-in-Picture, orientation lock, styled subtitles, and smooth playback for all formats.
Audio Player
Album-art backgrounds, waveform visualizer, built-in equalizer, variable speed, and background playback.
Audiobook Studio
Turn PDFs and EPUBs into professional audiobooks. Background generation with M4B, MP3, or ZIP export.
AI Narrator Voices
Dozens of natural-sounding offline voices across languages, genders, and styles — preview before generating.
Secure Vault
PIN or fingerprint-protected, encrypted storage invisible to other apps with swipeable gallery.
Text to Speech
Type or paste any text and hear it instantly; save as MP3 or WAV for later.
EPUB Reader
Chapter navigation, bookmarks, resume position, and one-tap switch to listen mode.
Chromecast
Stream video and audio to any Chromecast-enabled TV or speaker with remote controls.
AI product architecture
On-device document-to-audio pipeline
PDF and EPUB text is extracted and converted to speech locally, without uploading documents to a server.
Voice selection without cloud dependency
Users preview and choose from offline AI voices before generating audiobooks — no internet required.
Background generation architecture
Audiobook rendering runs as a background task so users can continue using the app while long books are processed.
Encrypted private media separation
Vaulted files are isolated from the media scanner and protected by biometric authentication.