Borderless Window Manager privacy statement

Data controller: Marduk Syndicate (United States). Contact: support@marduksyndicate.io.

• No network connections. No accounts, no telemetry, no analytics, no crash reports, no advertising. Nothing the app reads or records is sent anywhere, and we receive nothing from it.
• What it reads on your PC, to do its job: the titles, class names and program paths of open windows (and whether a program runs as administrator, so it can tell you it can’t manage that window); the key combinations you set as hotkeys, and only those; each monitor’s model and serial number, so it recognises a monitor after a reconnect; your Steam library’s folders and game manifests, to list games and detect their engine and any anti-cheat; and a game’s configuration file or registry value, only for a game you ask it to make windowed or borderless.
• What it stores, and where: your settings, rules, hotkeys, tab groups, remembered window positions, the History journal and the backups of any game setting it changed, as plain JSON and text files in %APPDATA%\BorderlessWindowManager on Windows or ~/.config/BorderlessWindowManager on SteamOS and Linux. Logs are kept for seven days. Settings has an “Open data folder” button.
• Outside that folder, only when you turn the feature on: the “Start with Windows” entry (on Linux, an autostart entry in ~/.config/autostart), and the game setting edits you asked for, each backed up and undoable.
• On KDE Plasma it reads and moves windows through a small script loaded into KWin while the app runs and unloaded when it exits. KWin scripts can’t see what you type.
• Diagnostics are yours to send. “Export diagnostics” writes a text file only when you click it, with your user-folder paths replaced so your user name doesn’t appear. Nothing happens to it unless you attach it to a report yourself.
• No Steamworks API. The app doesn’t report play time or anything else to Steam. Your purchase is handled by Valve under Steam’s privacy policy.
• Deleting everything: run Prepare for uninstall in Settings, uninstall through Steam, then delete the data folder above.

The website’s own privacy notice, including analytics, is on the privacy page.