Syncplay Droid

Syncplay Droid is a native Android client for watching videos in sync with people using Syncplay on Windows, macOS, or Linux. It is written in Kotlin with Jetpack Compose and Material 3 Expressive. Version 0.4.0 is MPV-only: the bundled libmpv engine handles all media playback, while AndroidX libraries provide the user interface and Android platform integration.

The app speaks the standard Syncplay TCP/JSON protocol directly. Other Syncplay clients can keep using their own players: each client controls its local playback while the Syncplay server coordinates play, pause, and position.

Features Join standard Syncplay rooms, including password-protected and managed rooms. Require STARTTLS by default, with certificate and hostname validation. Plain TCP remains an explicit compatibility option for older servers. Remember the server password using an AES-GCM key stored in Android Keystore. The secret is excluded from Android backup and device transfer. Play local files, Android document-provider files, direct SMB2/SMB3 sources, and HTTP(S) URLs through MPV. Keep playback running in the background with fullscreen landscape playback, immersive mode, an Android media notification, and system media controls. Browse SMB2/SMB3 shares directly inside the app. MPV uses a bounded loopback range bridge with positional reads and reconnect-once handling, so large remote MKVs remain seekable without depending on a file manager's sequential content:// pipe. Choose the file manager used to open videos and subtitles. MiX Explorer and other Storage Access Framework providers can return files from SMB locations without exposing SMB credentials to this app. Select internal subtitle tracks exposed by MPV, including text and bitmap tracks when the media provides them. The subtitle picker can switch tracks, disable subtitles, or open an external sidecar. Open external SRT, VTT, ASS, SSA, TTML, SUP/PGS, and Noir-compatible ZIP subtitles from a document provider or SMB. A selected sidecar replaces the previous external sidecar, and changing videos clears it. Customize subtitle appearance for text captions: font size, text and background colors, background opacity, position, maximum width, padding, weight, line height, letter spacing, corner radius, and text shadow. Appearance and timing preferences are stored locally. Start with Noir Player's GothamPro CSS font stack (downloaded and cached from its public CDN, with Android sans-serif as the offline fallback), choose local Android font families, or load TTF/OTF faces declared by another HTTP(S) CSS @font-face stylesheet. Set a subtitle offset from -120 to +120 seconds, optionally remember it, and use previous/next cue alignment for the selected text track. Export an offset-adjusted copy of the selected external text subtitle, including the first supported track in a ZIP. VTT stays VTT; SRT, ASS, and SSA are written as SRT. Internal and bitmap tracks are not exportable. Synchronize play, pause, and seek in both directions, with speed-based drift correction for small offsets and a direct seek for larger offsets. Use room chat, readiness, participant/file status, and shared playlist views when the server supports them. Adapt the Material 3 Expressive interface across portrait phones, short landscape windows, and tablet-sized layouts.