Sill is a free app that streams a window from your Mac, or its whole desktop, to your iPhone or iPad. You control it on the device with touch, a keyboard, a trackpad, or Apple Pencil, and the setup needs no account and no server between the two devices.
Sill streams one Mac window at a time over your own network
Sill for Mac lives in the menu bar. When a device picks a window, it captures that window, encodes it as hardware HEVC video, and sends it straight to the iPhone or iPad over an encrypted TLS 1.3 connection. The stream runs at up to 120 fps on ProMotion screens and 60 fps elsewhere, and seven quality presets range from Low at 4 Mbps to Extreme at 150 Mbps.
You pair each device once by scanning a QR code or typing a 12-digit code, and a USB cable pairs by itself. The app finds your Mac automatically over Wi-Fi or a cable, Direct Wireless Connection works when the two share no network, and Remote Access reaches your Mac away from home through your own VPN, such as Tailscale, or a port you forward on your router.
Sill needs a Mac with Apple silicon on macOS 14 or later, and an iPhone or iPad on iOS 17 or iPadOS 17 or later. The Mac app asks for Screen Recording and Accessibility permissions the first time you open it.
Touch, trackpad, and Apple Pencil controls cover the Mac side
On the device, you tap to click, drag to scroll with momentum, and touch and hold to right-click. Apple Pencil works as the mouse with hover, and software and hardware keyboards support command, control, and option shortcuts, along with a key row that has latching modifiers and a Spotlight key.
Hold an iPhone or iPad upright and Sill switches to a laptop layout, with the picture on top and a key row and trackpad below. The trackpad supports two-finger scroll, two-finger tap, and three-finger gestures for Mission Control, App Exposé, and switching Spaces, and each Mac app’s menus sit behind a Menus button. Window thumbnails let you switch windows with a tap, and an Apps drawer launches any installed app.
Sill follows the fold on iPhone Duo
Sill is already tuned for the foldable, which launches on October 23. Open flat on its side, the inner display shows your Mac, and half open like a laptop, the picture sits above the fold with a trackpad and keys below. Closed, Sill runs on the cover display, and nothing you touch sits on the fold.
Apple opened App Store submissions for apps optimized for the iPhone Duo earlier this month, which gives developers a few weeks of lead time before the launch.
Sill is open source, collects no data, and has a few limits
The iPhone and iPad app is a free download on the App Store from developer Noah Saffer, and the companion app, Sill for Mac, comes from the Sill website. Version 0.5 added support for iPhone Duo, and 0.5.1 is the current release.
Sill is licensed under Apache 2.0, with the source on GitHub, and the App Store listing says the developer does not collect any data from the app. An optional tip through GitHub Sponsors unlocks nothing, since every feature is free.
Sill shows one window or the whole desktop at a time, and it does not play sound from your Mac. Sill for Mac is a notarized download from the website rather than a Mac App Store app, because its optional virtual display uses a private macOS API.
The iPhone and iPad app is a 3.4 MB download, and Sill for Mac is a menu bar app of roughly 6 MB.
