The problem with screens in the home
A screen on the kitchen wall showing the family calendar sounds straightforward until you try to set it up. Shared logins. Device-specific apps. Keeping it updated when the household calendar changes. Getting a persistent display working well has historically required more effort than most families are willing to invest.
We wanted the wall display to work for the household that does not want to think about it after the first five minutes.
No app required on the display device
The most important decision we made early on was that the display device does not need an app. It just needs a browser. Any browser, on any device, including a ten-year-old iPad that no longer receives software updates, an Android tablet, a smart TV with a built-in browser.
This matters because app installations create ongoing maintenance. Apps need updating. Updates break things. Devices fall out of support. A browser just works.
The display is a URL. You visit it, it shows the calendar. If the browser restarts, you visit it again. That is the entire maintenance story.
How the six-digit pairing works
When you set up a display in Kerfuff, a six-digit code appears on the display screen. You enter that code in the Kerfuff app on your phone. The display is now linked to your household's calendar.
That is the entire process. No account on the display device. No logins. No credentials to share. The display shows your calendar without having access to your Kerfuff account itself.
The code is short because it is designed to be typed by a person looking at a screen from across the room. Six digits is easy to read at a distance and enter on a phone without squinting.
Security without the complexity
A display token is not a login. It gives the screen a read-only view of the family calendar. It can be revoked from the Kerfuff app at any time, and the display stops working immediately.
This matters if a device is lost, if the household changes, or if you simply want to remove a display from a device you no longer use. You do not have to track down credentials on a device you may no longer have access to.
The token is validated on every request from the display. There is no cached state on the device that outlives a revocation.
What we learned from testing it
The first version of the pairing used a QR code rather than a number. QR codes are harder to read from across the room and required a camera on the device doing the entry. The number won out.
We also tested longer codes. Eight digits felt like a barrier. Six struck the right balance: short enough to type without frustration, long enough to avoid collisions.
The display is designed to be forgotten about after setup. It updates automatically as calendars change. It does not need maintenance.