Nothing. Interlace has no account system, no analytics and no crash-reporting service of its own. We never see your Plex credentials, your library or what you watch.
Your Plex token, IPTV playlist and credentials, Seerr API key, favourites and watch positions are stored on the device (in the system keychain where the platform provides one). Deleting the app deletes them.
If you switch on “Sync across devices”, the same settings are copied to your private iCloud database so your Apple TV and iPad pick them up. Only you and Apple’s infrastructure can read that data; we cannot. Switch it off in Settings to stop and remove it.
Plex (plex.tv and your own server) for sign-in and your library; your IPTV provider for channels and the programme guide; TMDB and JustWatch for artwork and streaming availability; your Seerr instance for requests, if you connect one. Each of these sees the requests your device makes to it, under its own privacy policy.
Titles you take offline are stored in the app’s container on the device and are never uploaded anywhere.
Interlace is not directed at children and does not knowingly collect data from anyone.
This policy changes only when the app does something new with data; the date below is the last change. Questions: privacy@interlace.tv.