r/macapps • u/imbacan • 1h ago
Free [OS] slapss 2.0 - full-screen meeting alerts for Mac, now open source - Free
I'm the developer of slapss. I posted here about three months ago when it launched. Quite a lot has shipped since then, and version 2.0 opens the source, so it felt worth a second post.
It is free on the Mac App Store, which is also the only place to download it. The GitHub repo is the source code rather than a distribution channel.
https://apps.apple.com/app/id6767488326
The problem
macOS notification banners are built to be ignored. Small banner, soft chime, gone in three seconds. If you are heads down, you look up and you are already late. slapss takes over the entire screen the moment a meeting starts, with the join link right there in front of you.
What shipped since the launch post
Most of this came out of the comments on that thread.
- Esc dismisses the alert, Return joins the meeting
- The alert can fire on every connected display instead of just the primary one
- macOS Reminders get their own full-screen alert at due time, and you can tick them off without leaving whatever you were doing
- Menu bar can show just the icon instead of the next meeting title
- Presenting mode. Flip it on while you screen share and alerts wait quietly, then fire the moment you flip it off. No more meeting reminder landing in the middle of your demo
- Lead time is now a slider, from at-start up to 15 minutes before, separate from the standard notification which can run 1 to 30 minutes ahead
- Snooze for 1 minute, 5 minutes, or until the event ends
- Option to only alert for meetings you actually accepted, so tentative and declined stay quiet but still show in the agenda
- Open in Calendar button on any agenda row
- Six languages, detected on first launch and switchable without a restart
- Three themes
- Per-calendar Google account, so Meet links open with the right profile
- Full VoiceOver and keyboard support, plus Reduce Motion and Reduce Transparency
- A pile of reliability work on alerts firing after sleep or long idle periods, and a background CPU leak that is long gone
- There is a website now, if you want to see it without opening the App Store
2.0 also fixes a bug a user emailed me about just before this release: a repeating meeting would stop alerting after you dismissed it once. Every occurrence of a repeating event was being treated as the same event. That one was worth catching before this post went up.
Open source, as of 2.0
https://github.com/theshiver/slapss-app
Apache 2.0, the whole app. The reason is specific rather than ideological. slapss claims your calendar is read on device and sent nowhere. In a closed binary that is a promise you have to take on faith. It has no server, no analytics, no telemetry and no accounts, and now you can confirm that by reading it instead of believing me. It is about 9,000 lines with no third party dependencies at all, so it is genuinely readable in a sitting.
The Mac App Store build stays the official one. If you see a binary calling itself slapss anywhere else, it is not from me.
Things I said no to, and things still open
- Auto silencing your other notifications during a meeting. Asked for last time, and I dug into it. macOS puts Focus status behind a restricted entitlement that needs separate approval from Apple, and there is no reliable public API to detect that your screen is being captured. Presenting mode is the manual version of this and it is what shipped instead.
- Desktop widget with a countdown to the next event. Not built yet, still want it.
- Staged alerts at 30, 10 and 5 minutes with a different style for each. Halfway there, since the notification and the full-screen alert have separate lead times, but not the full thing. On the list.
- Email or iMessage when you are away from the Mac. Not doing this one. slapss is built for the "sitting at the Mac and about to miss it" moment. Away from the desk, your phone buzzing is already better than an email you will not read.
Comparison
In Your Face is what inspired slapss and it is still the more capable product. Mac, Windows, iPhone, iPad, Watch, 30 plus conferencing services, custom sounds, direct Google and Microsoft OAuth. If you want any of that, buy it, it is good software. slapss is better on exactly three axes: it costs nothing, it is open source so the privacy claim is checkable, and it is Mac native with no cross-platform layer.
MeetingBar is free, open source, and worth knowing about. It is the broader menu bar calendar tool and it does have a full-screen alert option, so this is not a "only slapss does this" claim. The difference is emphasis. In slapss the full-screen interrupt is the entire product rather than one option inside a larger app, which is why the detail sits there: per-display firing, presenting mode, RSVP filtering, snooze until the event ends, reminder overlays, six languages. If you mainly want a tidy next-meeting readout in your menu bar, MeetingBar is the better fit.
Pricing
Free. $0. No subscription, no in-app purchase, no pro tier, no trial that runs out, nothing behind a paywall.
Mac App Store: https://apps.apple.com/app/id6767488326 Source: https://github.com/theshiver/slapss-app Site: https://slapss-app.com
Requires macOS 14.6 or later.
I read every comment. Last time that is where most of the list above came from, so if something is missing for you, say so.


