Subvenio Screen

one hotkey between your Mac and 1984

Subvenio Screen lives in the menu bar and lays a film-grain, scanline, VHS or sepia look over your whole desktop - every app, the Dock, the menu bar. One hotkey turns it on, the same hotkey turns it off, and the effect is back exactly where you left it after a restart.

The seventeen presets that ship with the app, in the order the menu groups them, each rendered through the same shader the screen gets. These are offline renders of the picture the settings window previews on, because a screenshot of the real thing is unreliable: the overlay asks not to be captured, and whether that request is honoured depends on the version of macOS.

Features

• Seventeen presets out of the box, grouped in the menu by what they cost: free ones that rewrite the display table, ones that draw a layer over the screen, and ones that read the screen back.
• One global hotkey for the whole screen, recorded in settings, and a second one for stepping through the presets if you want it. No Accessibility permission needed.
• Live tuning. Presets that draw or read the screen carry their own sliders - grain strength, vignette, scanline depth - and moving them changes the running effect immediately. The four free ones are shaped by the gamma section of their manifest instead.
• A preview next to the sliders, so you can see what a preset does before putting it on the whole screen. It runs on a picture that ships with the app, so even the presets that read the screen preview without asking for anything.
• Window-only mode. Instead of the whole display, the effect can follow a single window as it moves and resizes.
• Pick your display when more than one is connected.
• Light on the machine. Capture size and frame rate caps are yours to set; the effect pauses when the screen sleeps and steps down in Low Power Mode.
• Stays out of the way. No Dock icon, no windows unless you open settings, and problems are reported quietly through the menu bar icon instead of a modal dialog. Animated presets respect the system "Reduce Motion" setting.
• Your own effects. Presets are folders with a Metal shader, not a fixed list. Drop one onto the settings window and it shows up in the menu without restarting the app, and editing the one that is running changes the screen as you save.
• Update check against the GitHub releases page - weekly by default, or daily, monthly or never, and there is a Check now button. The app never downloads or installs anything by itself; it tells you a version is out and opens the release page.
• English and Russian interface. Launch at login is one checkbox.

Install

1. Download the .dmg from the Releases page.
2. Open it and drag Subvenio Screen into your Applications folder.
3. The build carries an ad-hoc signature and is not notarized, so Gatekeeper blocks it on the first launch. Open it once, let macOS refuse, then go to System Settings → Privacy & Security, scroll down and click Open Anyway. On macOS 14 the shortcut still works: right click (or Control-click) the app and choose Open. Apple removed that shortcut in macOS 15.

After the first launch macOS remembers the choice and opens the app normally.

Every release note carries the SHA-256 of its disk image. An ad-hoc signature says nothing about who built the file, so the sum is what there is to compare:

shasum -a 256 "Subvenio Screen 1.7.2.dmg"

If the app is reported as "damaged", the quarantine flag is the cause. Clear it once in Terminal:

xattr -dr com.apple.quarantine "/Applications/Subvenio Screen.app"

The app checks the Releases page for a newer version - once a week unless you change it in settings - and tells you in its menu when one is out. Installing is still a manual step: a new version means a new disk image from Releases.

macOS remembers a permission against the app's designated requirement, and for an ad-hoc signature that requirement is the hash of one particular build. Every update is therefore a different app as far as the system is concerned: the eight presets that read the screen ask for Screen Recording again after one. The nine that need nothing are unaffected.

macOS 15 added a second prompt of its own. An app that takes the whole screen without going through the system picker is asked to confirm that roughly once a month, and this one takes the whole screen by design.

The presets

Preset	What it does	Cost
Invert	inverts the picture, cursor and menu bar included	free
Sepia	warm tint with lifted blacks	free
Faded Photo	washed-out warm tint, a photo left in the sun	free
Moonlight	blue and dimmed, the day-for-night trick from film	free
Scanlines	CRT lines over the screen	one drawn layer
Film Grain	flickering grain with a vignette	one drawn layer
VHS	purple tint, line noise and a drifting band	one drawn layer
Dust & Scratches	film wear: scratches and specks, each one frame long	one drawn layer
Projector	even lamp light, the corners in shadow	one drawn layer
Black and White	true desaturation, not a tint	reads the screen
Phosphor Terminal	luminance poured into one phosphor, amber or green	reads the screen
Aperture Grille	every third column to its own phosphor	reads the screen
Halation	light spreading past the edge of what emits it	reads the screen
Chromatic Aberration	channels diverging towards the edges	reads the screen
Halftone	newspaper printing, the grid turned 45 degrees	reads the screen
1-bit Dither	black and white with a Bayer pattern between them	reads the screen
Game Boy	the four DMG shades and dithering between them	reads the screen

The eight presets that read the screen ask for the Screen Recording permission, and only when you turn one on by hand rather than on autostart. The other nine work without any permission at all, and refusing leaves them fully usable.

Swiping between spaces drops every preset except the free four for about a second, until the new space settles. macOS assembles that animation in the compositor and leaves ordinary windows out of it, so a drawn layer cannot be shown during the switch at any window level. The free four are not drawn as a layer at all - they are a table applied to the display itself, after everything else - so they are the ones that stay on through the transition.

The last three are worth a warning: quantising the screen to two shades or four makes small text hard to read. They are effects to look at rather than to work under.

Captured frames live in memory just long enough to be drawn. Nothing is written to disk and nothing leaves the machine.

Your own effects

A preset is a folder with a manifest.json and a Metal fragment function. Drop the folder onto the settings window and it installs itself; New preset from template writes a working one for you and shows it in Finder; Open shaders folder takes you to the rest. Save a file and the menu updates itself, no restart - and if you edit the preset that is currently on screen, the screen follows. A broken preset shows the actual error instead of quietly disappearing: a manifest that does not parse is named in the menu, a folder that holds no manifest at all says so, and a shader that does not compile shows the compiler's message under the preview.

A preset can name its own menu bar icon and describe itself in a line that shows up under the preview and as a tooltip in the menu, in English or in Russian.

The bundled presets are yours to edit, and yours to delete. An edited one stays as you left it even when a new version of the app ships a different version of the same preset, a deleted one stays deleted, and Restore bundled presets in settings puts them all back the way they came.

The format is described in DEVELOPMENT.md.

A preset someone hands you is code, not a picture. It is Metal source that this app compiles and runs on your GPU. The app runs inside the App Sandbox, so a preset cannot reach your files or the network, but it can still draw whatever it likes over your whole screen and cost as much GPU time as it wants. Read a shader before you drop it in, the same way you would read a script.

Known limits

• One effect on one display at a time. You choose which display, but independent presets on several monitors at once are not implemented yet.
• The four free presets share the display's gamma table with Night Shift, f.lux and any custom calibration, and the last one to write it wins. Turning such a preset off restores every display to its ColorSync profile, because the public API to undo a gamma table has no per-display counterpart; whatever else had tinted the screen applies itself again on its own schedule.
• The four free presets cover the whole display by nature and cannot be confined to a single window.
• The overlay asks not to be captured, so on macOS 14 the effect will not show up in a screenshot or a recording of your own screen. macOS 15.4 stopped honouring that request for apps recording through ScreenCaptureKit, so a capture made there may well include it.
• Apple Silicon only.

Under the hood

Built from source with make run; the details live in DEVELOPMENT.md, and the reasoning behind the architecture in PLAN.md. What changed between versions is in CHANGELOG.md.

License

BSD 3-Clause. The one dependency, KeyboardShortcuts, is MIT.