Every change Rein makes that could outlive it is undone when you quit Rein, if it crashes, and when you press Reset to Auto: fan control goes back to macOS, the charge limit is cleared, keep-awake and the lid-closed hold are released, display gamma and brightness boosts are restored, and muted apps get their sound back. The worst case is always plain macOS behaviour.
macOS asks before Rein can use any of these. Each is for the features beside it; if you refuse one, only those features stop working.
| Permission | Used for |
|---|---|
| System audio recording | Per-app volume, EQ, routing and recording in the Audio pillar |
| Microphone | Only when you add a physical input to a virtual audio device |
| Accessibility | Menu-bar tidy, the brightness keys, and the phone remote’s mouse and keyboard |
| Screen recording | The phone remote’s live view of your screen, and casting your screen to a TV |
| Calendars | Only for the rule that keeps the Mac awake during calendar events |
| Local network | Finding and streaming to a Chromecast or Google TV |
| Background item (the helper) | Fans, charging and lid-closed keep-awake; approved in System Settings |
Changing fan speeds and charging means writing to the Mac’s System Management Controller, which only root can do. Rein keeps that in one small helper, installed through Apple’s own SMAppService and approved by you in System Settings. The helper does three kinds of job and nothing else:
pmset disablesleep), scheduled wake and sleep, and “sleep now” from the phone remoteThe helper only accepts requests from a copy of Rein signed by the same developer (Team ID TTDV2PKXT8), and Rein only talks to a helper with that signature: the check runs both ways. To remove it: Rein → Settings → Remove helper, or System Settings → General → Login Items & Extensions. Without the helper, everything except fans, charging and lid-closed keep-awake still works.
On the firmware that ships with macOS 26.7, 15.8 and 27, the 80 to 100 percent limit is Apple’s own setting: Rein writes it without the helper, through the same client System Settings uses, and it shows in System Settings → Battery. Rein clears it when you quit, or puts back the value you had set yourself.
Rein Audio is a virtual loopback device: sound played to it can be recorded from it. It is installed only when you turn on virtual devices in the Audio pillar, and lives at /Library/Audio/Plug-Ins/HAL/ReinAudioDriver.driver. It makes no network connections. To remove it: Audio → Virtual devices → Turn off.
| What | When | Where to, and what is sent |
|---|---|---|
| Update check | Once a day; switch off in Settings → Updates | Asks raw.githubusercontent.com whether a newer version exists. Updates download from GitHub and are checked against Rein’s signing key before they install. |
| Licence activation | Once, when you unlock with a code | Sends your code (which carries the email you bought with), Rein’s version, and a one-way device number (a salted hash that cannot be turned back into your Mac’s serial) to rein-licence.long-bird-a145.workers.dev. It counts how many Macs use a code; it never blocks one. Checking a code happens on your Mac, offline. |
| Casting | When you cast | Only to the Chromecast, Google TV or AirPlay device you pick, on your own network. |
| Rein Remote | Only if you set it up | Through a small relay that Rein deploys to your own free Cloudflare account. Traffic between your phone and your Mac is end-to-end encrypted (ChaCha20-Poly1305, with keys from the pairing code), so the relay sees only scrambled data. Setting it up sends the Cloudflare token you paste to api.cloudflare.com, and nowhere else. |
| Browser remote | Only if you set it up | Also on your own Cloudflare account. It needs your pairing code, and you can put an email sign-in in front of it. |
That is the full list. Rein has no accounts, analytics, telemetry, crash reporter or ads. A network monitor such as Little Snitch or LuLu will show you exactly these connections and no others.
~/Library/Preferences/com.lukedavid.Rein.plist~/Library/Application Support/Rein/history.dbTo remove Rein completely: remove the helper and turn off the audio driver as above, quit Rein, delete it from Applications, then delete those two files.
Rein is made by one independent developer, with AI coding tools. The seller is named in the terms. Every copy is signed with an Apple Developer ID (Team ID TTDV2PKXT8) and notarised by Apple. To check yours, in Terminal:
codesign -dv --verbose=2 /Applications/Rein.appspctl -a -vv /Applications/Rein.app
The first should list TeamIdentifier=TTDV2PKXT8; the second, source=Notarized Developer ID. Each release on GitHub lists the SHA-256 of its Rein.dmg; compare it with shasum -a 256 ~/Downloads/Rein.dmg.
ffmpeg and ffprobe, for casting files a TV cannot play directly. It is built from git.ffmpeg.org/ffmpeg.git, branch release/8.1, commit 7ba069f4f11d, with no GPL or non-free options. The exact commit, build options and licence text ship inside the app, in Rein.app/Contents/Resources/FFMPEG-SOURCE.txt and FFMPEG-LICENSE.txt.Email tidbit-people.1u@icloud.com. If something on this page turns out to be wrong, that is a bug, and it will be fixed on this page and in the app.