Flobro

Floating browser window for Mac and Windows, built with Tauri 2.

Float any webpage in a frameless, always-on-top window. No interface at all until you move your mouse to the top edge, where a toolbar appears with zoom, 16:9 snap, pin, minimize, settings and close.

Install

Grab the latest installer from flobro.app or the releases page.

On macOS, Homebrew works too:

brew install --cask flobro/tap/flobro

The cask lives in flobro/homebrew-tap and bumps itself automatically when a release is published.

Architecture

src/                  Launcher + settings UI (plain HTML/CSS/JS, no framework)
  i18n.js             UI translations (English primary, Dutch second)
src-tauri/
  src/lib.rs          Commands, deep link handling, privacy-friendly analytics
  src/toolbar.js      Hover toolbar injected into every float window (shadow DOM)
  capabilities/
    default.json      IPC for local launcher/settings windows
    float.json        Minimal IPC surface for remote pages in float windows

Each floating window loads the target URL directly in the OS webview. The toolbar is an initialization script injected at document start. It lives in a closed shadow root so page CSS can't touch it, and it only talks to a small set of float_* commands.

Security note: the float capability grants remote pages access to app IPC. The exposed surface is deliberately tiny (window controls only), but review capabilities/float.json before adding commands.

Deep links

The app registers the flobro:// URL scheme. The Chrome extension (and anything else) can hand a page to the app:

flobro://open?url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3D...

Single-instance handling makes sure the link lands in the running app instead of starting a second one.

Analytics

Usage stats go to PostHog (EU cloud) and are deliberately minimal:

• events: app_opened, float_opened
• float_opened carries only the hostname (like youtube.com), never the full URL
• no IP storage ($ip: null), random anonymous id, no other profiling
• users switch it off in Settings ("Share anonymous usage stats")

Set POSTHOG_KEY in src-tauri/src/lib.rs to your project key. While the placeholder is in place, nothing is sent at all.

Languages

English is primary, Dutch is included. UI strings live in src/i18n.js and toolbar.js; add languages there as usage data shows demand.

Develop

Prerequisites: Rust plus the Tauri prerequisites for your OS.

cargo install tauri-cli --version "^2"
cargo tauri dev

Build installers

cargo tauri build            # produces .dmg (macOS) or .exe/NSIS (Windows)

Or push a tag; the GitHub Actions workflow builds a universal macOS .dmg and a Windows NSIS installer and attaches them to a draft release:

git tag v1.0.0 && git push --tags

Code signing policy

macOS builds are signed and notarized with an Apple Developer ID. Windows builds are not code signed yet (Windows may show a SmartScreen warning on first run; choose More info, then Run anyway); free signing through SignPath Foundation is planned once the project qualifies. All release binaries are built by GitHub Actions directly from this repository.

Committers and reviewers: members of the flobro organization. Approvers: organization owners. Every signing request is approved manually.

Privacy: the app only transfers the anonymous usage statistics described in the privacy policy, and only while that setting is on.

Settings

Stored as JSON in the platform config dir (e.g. ~/Library/Application Support/app.flobro.desktop/settings.json). Default page, open-on-launch, stay-on-top default, recent pages, and the analytics opt-out.

License

MIT.