FREE · OPEN SOURCE · FOR MACBOOK
Duo animation for Mac.
Free and open source.
Still brings iPhone Duo-style fold animation to your MacBook: close the lid and your desktop tilts, frosts over and dims.
A free, MIT-licensed macOS menu bar app. Build the prototype from source, or try the demo below.
Drag the laptop or move the slider. The seated view is what you'd see at your desk.
Browser simulation · the real app uses your actual desktopHow to get free Duo animation on your MacHOW IT WORKS
A snapshot, a hinge angle,
and one Metal shader.
Newer MacBooks have a lid angle sensor in the hinge. Still reads it over IOKit HID about 30 times a second. Nothing happens while you work; the app sits in the menu bar and waits for the lid to drop about 4° below the angle you normally sit at.
When it does, Still grabs a single ScreenCaptureKit snapshot of the built-in display and puts it on a borderless overlay. A Metal shader then does the trick Apple's foldable does: it projects that picture back onto the plane your screen was in a moment ago, from where you're sitting, so the desktop looks like it stays put while the glass moves over it. As the lid comes down the picture frosts over and the top shades to dark glass.
Open the lid back up and the overlay is gone, snapshot discarded. It never captures video or audio, never writes anything to disk, and makes no network requests. You'll still see macOS's Screen Recording indicator, because that's the permission the snapshot API lives under.
WHICH MACS
Needs a hinge sensor.
Not every MacBook has one.
Apple started fitting a lid angle sensor in the 16-inch MacBook Pro in 2019 and in the Air from the M2 in 2022. The M1 Air and every 13-inch MacBook Pro never got one, so on those Still can only play the effect from a button. This list comes from community testing around the LidAngleSensor project, not from Apple. If your model isn't on it, run the app anyway and tell me what the "Your Mac" tab says.
| Mac | Follows the lid | Notes |
|---|---|---|
| MacBook Pro 14-inch and 16-inch, 2021 onward (M1 Pro/Max, M2, M3, M4 families) | Yes | Sensor readable on the standard HID sensor page |
| MacBook Pro 16-inch, 2019 (Intel) | Yes | The only Intel Mac with the sensor |
| MacBook Air M2 (2022), 15-inch M2 (2023), M4 (2025) | Yes | Reported working by the community |
| MacBook Air M3 (2024) | Probably | Has the hardware, model identifiers not yet confirmed |
| MacBook Air M1, every 13-inch MacBook Pro | Manual only | No lid angle sensor in these machines |
| Mac mini, Mac Studio, iMac, Mac Pro | Manual only | No lid to follow |
Still needs macOS 14 Sonoma or later and Screen Recording permission. Apple Silicon is what it's built for; Intel builds are untested.
QUESTIONS
Things people ask
before they build it.
How do I get Duo animation for Mac for free?
Try Still's browser demo, then download the free source code and build the macOS app with Xcode Command Line Tools. Automatic MacBook lid animation needs a readable lid angle sensor; the manual preview can show the effect without one. Still is an early prototype, not a notarized installer. Follow the Duo animation for Mac setup guide.
Is Still's Duo animation app open source?
Yes. Still's Swift, Metal and JavaScript source is published on GitHub under the MIT license. You can inspect, modify and redistribute it under the license terms. There is no subscription, activation key or paid tier. Read the source and license on GitHub.
Is Still really free?
Yes. The whole thing is MIT licensed and the source is on GitHub. You build it yourself with the Xcode Command Line Tools (two commands, no Apple developer account), or grab the build from the GitHub Actions run. There is no paid tier and I'm not planning one for this prototype.
Is this the same as Bendy?
No. Bendy is a paid, closed source Mac app with the same idea, and it has been tested on real hardware. Still is a free, open source take that's still early. If you want something polished and notarized today, buy Bendy. If you'd rather read the code and tinker, you're in the right place.
Does it work on an M1 MacBook Air?
The manual preview does. Automatic lid tracking doesn't, because the M1 Air and every 13-inch MacBook Pro have no lid angle sensor. An open/closed switch can't drive a continuous animation.
Does Still record my screen? macOS says it wants to record screen and audio.
No. It takes one still image of the built-in display when the lid starts to close, keeps it in memory for the gesture and throws it away. No video, no audio, nothing written to disk, no network requests. The dialog that says Still "would like to record this computer's screen and audio" is Apple's standard wording for the Screen Recording permission, shown to every app that asks for it; there is no separate "one screenshot" permission. Still calls the snapshot API with audio disabled and never opens a recording stream. You can read exactly what it does in ScreenCapture.swift, about 40 lines.
Has it been tested on real Macs?
Not enough yet. The geometry has unit tests and the code is written, but I built this on a Windows PC and it needs people with sensor-equipped MacBooks to run it. If that's you, open an issue with your model identifier and what the app said. That's the most useful thing anyone can do for it right now.
Does it run on Windows?
Not yet. Windows has a HingeAngleSensor API but almost no laptops expose it, so a port would be manual-only for most people. If you have a hinged dual-screen device and want to help test, say so on GitHub.
FREE DOWNLOAD · OPEN SOURCE
Your MacBook lid animation.
Build it from source.
Download Still's free Duo-style animation source for Mac. The build script creates Still.app in native/build and runs geometry tests when full Xcode is installed. No Apple developer account required.
ON YOUR MAC
Install Duo-style animation
on your Mac in six steps.
Build Still from source with the steps below. For requirements and troubleshooting, read the free Duo animation for Mac guide. If a step fails, include the terminal output and your model identifier in a GitHub issue.
Unzip and open a terminal there
Double-click
Still-source.zipin Downloads, then in Terminal:cd ~/Downloads/Still-sourceCheck the developer tools
You need Apple's command line tools, not full Xcode.
xcode-select -pIf that prints a path you're set. If it errors, run
xcode-select --install, click Install, wait a few minutes, then carry on.Build
bash native/scripts/build.shWith full Xcode installed the tests run first. With only the Command Line Tools the script says it's skipping them (XCTest ships inside Xcode) and builds the app anyway. Red text after that is a compile error: paste it into an issue.
Open the app
open native/build/Still.appThe Still window appears with the slider preview. That part needs no permissions. Still also lives in the menu bar; the icon is a tilted rectangle.
Allow Screen Recording and read the sensor line
In the Your Mac tab, click Allow. macOS opens System Settings; switch Still on, then quit and reopen the app if it asks. The line above it says either "Lid sensor available" with a live angle, or "No readable lid-angle sensor". Note the model identifier under it, something like
Mac15,3.Try it
Click Preview on desktop for a four-second run on your real desktop. If the sensor was found, click Use current lid while sitting normally, switch on Follow lid, and close the lid slowly. Open it back up and the effect clears.
If Terminal says "Operation not permitted" inside Downloads, macOS is blocking it from that folder: allow Terminal under Privacy & Security → Files and Folders, or move the folder to your home directory first. Built locally, so Gatekeeper won't complain; it's signed ad hoc on your own machine. That also means macOS forgets the Screen Recording permission after each rebuild, which is normal for unsigned dev builds.