Rainy Day

Some screensavers shout. Slideshows, cycling animations, your beach holidays on rotation. Rainy Day is the opposite.

Drops gather on a glass pane and slip down with realistic gravity, refracting the world behind them as they pass. Larger drops absorb the smaller ones in their path and shed trail droplets behind. The whole pane carries a fine mist of tiny droplets that comes and goes.

Eight scenes, fade-through-dim

The world behind the rain is a photograph — and Rainy Day rotates through eight of them, one every five minutes (configurable, 1–30 minutes) with a gentle three-second fade-through-dim transition between scenes. The seed set on first launch is a curated mix of city streets and quiet landscapes; you can swap any of them out at any time without rebuilding the app.

Every scene rotation is in lockstep across multiple displays, so a quick glance from one screen to another stays in the same mood. Rain physics is independent per display — mirroring the drops exactly across separate WebGL contexts is hard, and the visual cost of letting them drift is essentially zero.

Rain on glass over a soft-focus coastline: green cliffs falling to a grey-blue sea, distant headland, low cloud. — **Coast** — cliffs falling away to a grey-blue sea, low cloud above the headland.

Rain on glass over a misty forest valley: a stream winding through dark conifers, soft fog drifting between the slopes. — **Forest valley** — a stream threading through dark conifers, fog softening the slopes.

Rain on glass over the Seine at golden hour: warm sky, the Conciergerie's domes catching the last light, the river still beneath them. — **Seine, golden hour** — the Île de la Cité catching the last light, the river still beneath.

Rain on glass over Westminster Bridge and Big Ben at dusk: a teal-grey London sky, lamps just beginning to glow on the bridge. — **Westminster at dusk** — Big Ben and the bridge in a teal-grey London sky.

Custom backgrounds

The eight photographs live in ~/Library/Application Support/Rainy Day/Backgrounds/. The folder is yours after first launch — drop in JPG, PNG, HEIC, or WebP files; rename or remove anything you like. The screensaver scans the folder fresh on every activation, so it always reflects what’s on disk.

If the folder is empty, the screensaver shows a centred notice telling you where to drop images instead of failing silently. Settings has an Open Backgrounds Folder button that takes you straight there.

The rain

The rain itself is a WebGL2 effect — raindrop-fx by SardineFish. It does refraction the way real water on glass does it: each drop samples and warps the scene behind it through screen-space normals, with diffuse and specular lighting for depth. Drops slide with gravity, merge on contact, shed trail droplets as they pass, and slowly evaporate. The bundle ships unmodified inside Rainy Day; without raindrop-fx the screensaver wouldn’t exist.

Rainy Day’s contribution is the host: a thin Swift app that renders raindrop-fx fullscreen inside a WKWebView on every connected display, handles activation and dismissal cleanly, and tunes raindrop-fx’s parameters so the drops feel right at screen scale.

Why an app, not a `.saver`

Rainy Day is a screensaver-style product, but it ships as a regular .app rather than a .saver bundle. The screensaver-bundle path forced a long string of fights with macOS — process suspension, permission churn, multi-instance lifecycle, occlusion edge cases, removed SPIs — none of which add anything for the user. As a regular app it gets out of its own way, and gives full control over the configurator, hotkeys, and lock-screen integration that a saver bundle can’t reach.

It auto-launches at login, hides itself in the background as a small cloud-with-rain menu-bar icon, and brings up the fullscreen rain effect on every display when you’ve been idle past your configured threshold. Move the mouse or press any key to dismiss.

Settings

Click the menu-bar icon and choose Settings…:

Permissions › Accessibility — current status, with a Grant Access button. Required only if you turn on Lock screen when dismissed; that feature posts the system Lock Screen keystroke and needs Accessibility to do so.
Activation — idle timeout in minutes, plus a global Activate Now hotkey if you’d rather summon the rain on demand.
On dismiss › Lock screen when dismissed — off by default. With it on, the screensaver fades straight into the lock screen rather than back to the desktop.
Capture — a global hotkey that snaps the current rain frame to ~/Pictures/Rainy Day/. Saves the moment that caught your eye without breaking the screensaver.
Backgrounds — scene cycle interval (1–30 minutes), and an Open Backgrounds Folder button.
Wallpaper › Use as animated desktop wallpaper — renders the rain at the desktop layer, behind app windows and desktop icons, click-through. It’s independent of the screensaver-on-idle behaviour; both can be on at the same time. Note: as an animated wallpaper, the effect renders continuously while your Mac is awake — on Apple Silicon this is GPU-cheap but not free, so on a portable expect a small hit to battery life versus a static wallpaper.
General › Launch at Login — on by default after first install. Disable here or in System Settings › Login Items if you’d rather start it manually.

All settings persist immediately. There’s no Save or OK button.

Auto-updates are handled by Sparkle. New versions check daily in the background and are EdDSA-signed, so your copy will only install genuine Jorvik Software releases. Use the menu’s Check for Updates… item to check on demand.

Privacy

No telemetry. Nothing is reported, and no log file exists unless you explicitly turn one on with defaults write cc.jorviksoftware.RainyDay debugLogging -bool YES. The only network request Rainy Day makes is Sparkle’s daily appcast fetch.

Installation

Two formats on every release — both signed and notarised, pick whichever suits:

Installer (.pkg) — recommended for first-time installs. Double-click to run; macOS Installer places Rainy Day.app in /Applications/ without quarantine or App Translocation.
Download (.zip) — unzip and drag Rainy Day.app to your /Applications/ folder.

Either way, the first launch happens immediately. After that, look for the cloud-with-rain icon in your menu bar — that’s your touchpoint with the app. Rainy Day registers itself for launch at login on first run; toggle that off in Settings › General if you’d rather start it manually.

To uninstall: pkill -f "Rainy Day" in Terminal, then drag Rainy Day.app from /Applications/ to the Trash.

Requirements

macOS 14 (Sonoma) or later. Universal binary (Apple Silicon and Intel).

Building from source

Rainy Day builds via the shared Jorvik release.mk. With the jorvik-release sibling repo cloned alongside it and GNU Make 4 installed:

Clone the repo: git clone https://github.com/PerpetualBeta/RainyDay.git
For a local install signed with the Jorvik Developer ID: gmake dev-build
To run the freshly-built copy: gmake run
For a signed, notarised, stapled .pkg ready to ship: gmake release

Credits

Rainy Day embeds raindrop-fx by SardineFish (MIT). The vendored bundle is raindrop-fx.bundle.js, unmodified from upstream. Every drop, every trail, every refraction is raindrop-fx’s work — the Jorvik side is just the host.

The eight bundled background photographs come from Unsplash photographers under the Unsplash License — free for personal and commercial use, no attribution required, but credit is given anyway.

Full licence text in ATTRIBUTIONS.md.

Installer Download .zip Source Code