Show HN: I built a HUD-like timer for macOS that stays visible in full-screen

Hi HN,

I’ve just released my first Mac App Store app, Buoyant Timer (paid, no in-app purchases)

It’s a lightweight HUD-like timer that floats above everything else on macOS, even full-screen apps.

I always wanted something like a configurable HUD for macOS. An app, or set of apps that stay visible at all times: a timer, runtime notes and scriptable alert/notification display.

This app is the first item on that roadmap. Something simple for deep focus where I switch between full-screen apps a lot, and often lose track of time.

What's under the hood?

This will probably be no news to seasoned Swift developers, but I was surprised by how much can be done with NSPanel.

So, the main view is a non-activating, borderless NSPanel:

    NSPanel(
      level = .floating,
      collectionBehavior = [.canJoinAllSpaces, .fullScreenAuxiliary]
    )
    orderFrontRegardless()

This keeps it always on top. There’s also a pass-through mode (ignoresMouseEvents = true) so clicks go to the app underneath uninterrupted.

Features

- Stopwatch and adjustable countdowns

- Pass-through clicks so it won't interrupt your workflow

- Global hotkeys

- Auto-start stopwatch when countdown ends (proved helpful on occasion)

- Customizable colors, opacity, and high-contrast mode

- Minimal interactive panel when you don’t want pass-through

I’d love to hear feedback, whether on the app, feature requests or anything else :)