The knock instead of a shortcut
A $5 Mac app that hides the screen when you knock the laptop, on M2 or an M1 Pro, with the license emailed and local tax added at checkout.
- Category
- Productivity
- Who it is for
- Someone on a MacBook who gets walked in on.
- Possible model
- Usage-based
- Difficulty
- Medium
- Inspired by
- KnockKnock · KnockKnock
- Original launch
- Watch the launch · Oct 15, 2026
Difficulty is an editorial estimate of technical and operational complexity, not a score.
Startup idea analysis by Startup Ideas. Last reviewed Oct 15, 2026. How we read a launch.
The startup idea
Akhil Menon posted KnockKnock on October 15, built with Shristy. Knock twice on the MacBook. Every window hides, a decoy takes over, and the sound mutes. Knock again and it comes back. $5 once, at knockknockmac.app. A reply says the motion sensor tells a knock from typing, sliding the laptop, or bumping the desk, and it calibrates in four knocks. A triple knock can lock the screen, mute the mic, or sleep the display. Detection runs on the Mac. Nothing leaves it. MacBooks with M2 or later, or an M1 Pro. The page repeats the $5, and adds local tax at checkout. The license code is emailed to an address that cannot be changed on the payment page. Up to 3 Macs. All future updates. No subscription. The hero says every window hides behind a spreadsheet. A later step says a decoy app slides in, and apps that refuse to hide get the wallpaper, a black screen, or your image. The page also says four knocks to calibrate. This page did not buy it.
The opportunity is the gesture a person can do without remembering a shortcut. A smaller product is two knocks and a spreadsheet. The post says a decoy app. The first screen on the site is specifically a spreadsheet.
Do not say it works on every Mac. The page names M2 or later, or an M1 Pro. Do not say the $5 is the amount charged. Tax is added.
The problem
Someone walks in. The shortcut is the thing you cannot remember.
Who would pay for this?
- Primary
- Someone on a MacBook who gets walked in on.
- Secondary
- A person who will not send a knock to a server.
- Early adopter
- One laptop, four calibration knocks, one hide.
How could it make money?
Possible models. Nothing here is a claim about what KnockKnock charges.
- $5 once, plus local tax at checkout.
- Up to 3 Macs. No subscription.
- The license arrives by email.
What would the MVP look like?
- Two knocks hide the windows and mute the sound.
- A spreadsheet, or the decoy the later section names.
- A triple knock for lock, mic, or sleep.
- The tax line next to the $5.
How to validate the idea
- Ask five people to hide a real window with a knock and bring it back.
- If typing also hides the screen, the calibration was the product.
- Do not add a subscription. The page says there isn't one.
How to differentiate
- The sensor is already in the laptop.
- Nothing leaves the Mac.
- The price is once.
- Do not become a shortcut app with a new key to memorize.
Why this could be interesting now
The post and the page agree on the knock, the $5, the on-device detection, and the Macs it supports. The page adds the tax, the three Macs, and a spreadsheet where the post says a decoy. The opening is one knock a person can do without looking.
Original product launch
This launch is inspiration and evidence that someone shipped, not a partnership. The idea above is our reading of the broader opportunity. KnockKnock did not write it.
- Product
- KnockKnock
- Company
- KnockKnock
- Film
- KnockKnock, the knock that hides the screen
- Posted
- Oct 15, 2026 · 0:29
Product that inspired this idea
Akhil's post says KnockKnock is a boss key you knock. Two knocks hide every window, a decoy takes over, and the sound mutes. Knock again and it returns. $5 once. A reply says the Mac's motion sensor tells a knock from typing, and it calibrates in four knocks. A triple knock can lock the screen, mute the mic, or sleep the display. Detection stays on the Mac. MacBooks with M2 or later, or an M1 Pro. The page says the same price, and adds local tax at checkout, a license emailed to an address you cannot change on the payment page, and up to 3 Macs. The hero says the windows hide behind a spreadsheet. A later section says a decoy app. Nothing leaves the Mac. No subscription. This page did not knock a laptop.
Posted by @akhilmn18. Watch the original launch. No separate product site is listed unless the post itself is the source.
- mac
- privacy
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