Sine: Audiobook Player MP3/M4B

Sine is an audiobook player for iOS — built for readers who listen.

Import your own MP3, M4B, M4A, FLAC, and AAC files via Files, AirDrop, WiFi upload, URL download, or share extension. Then listen with the controls audiobook readers actually want:

• Variable speed (0.5×–4.0×) with per-book memory
• Chapter navigation and bookmarks with notes
• Sleep timer with gradual fade and shake-to-resume
• Smart rewind on resume
• Folders, search, and custom drag-and-drop ordering for books and folders
• 10-band equalizer with presets and a custom slot
• Volume boost and normalization
• Gesture mode (tap zones on artwork to control playback)
• Dynamic player colors (tints from the book's artwork)
• Lifetime listening stats with daily, weekly, and monthly charts
• CarPlay and Apple Watch remote (both in beta)
• Lock screen, AirPlay, and headset buttons
• Interactive playback widgets, Siri Shortcuts, Spotlight search
• Full VoiceOver accessibility

SKIP SILENCE (BETA)

Most audiobooks contain hours of silent gaps and trailing pauses — skip them automatically and save real time over the course of a book. Tune the sensitivity to your taste, see your lifetime savings, and listen faster without missing a word. Skip Silence is in beta: turn it on and it starts automatically when you play a book.

PRIVACY-FIRST

No Sine account required. No ads. Your library is stored locally. Optional usage analytics help improve the app: feature events, listening-time ranges, a random installation identifier, and app and OS versions. These analytics do not include book titles, file names, or audiobook content. You can turn off usage sharing in Settings.

Built from scratch with SwiftUI, AVAudioEngine, and SwiftData. Zero third-party dependencies.