Why another screen time app?

For a long time we watched our kids use the same bag of tricks as their friends: change the clock. Delete the app and reinstall it. Sign in with a different account. Open the web version in the browser. Every time back to square one.

familydevice uses Apple’s Screen Time interface for parents — and closes those gaps. Setup is only finished once every lock is in place: deleting the app, revoking access, changing the clock, changing the device passcode, switching accounts, installing new apps — only with you. Blocked apps are blocked as websites too, in every browser. And the kid’s iPhone keeps checking these locks: if one is missing, your iPhone shows “weakened” and the reason why.

And because families need more than a bedtime, there is more than schedules: daily limits per app (“45 minutes of Roblox, 90 at weekends”), if-then rules (“if the iPhone wakes up at night, let me know and lock everything until morning”), an “Always Allowed” list, safety switches and your own network rules right down to the single domain. All from the parent’s iPhone, all enforced by the kid’s iPhone itself.

The four rules

• Honest about limits. Anyone who knows your passcode can erase an iPhone. We don’t prevent that — but you’ll notice, because the iPhone stops checking in.
• No data with us. There is no familydevice server. Your iPhones talk to each other directly, on the go through your own iCloud — end-to-end encrypted. Which apps are blocked is known only to the kid’s iPhone itself.
• Asking instead of circumventing. A kid who needs 15 minutes to text Grandma taps “Request more time” on the block screen. You approve with one tap, right from the notification. That’s the deal.
• Nothing in secret. Every if-then rule is shown on the kid’s iPhone in plain words under “Your parents get notified”. Your kid sees their own usage, steps and network — no PIN needed. Places only report “arrives” and “leaves”; the movement profile is off until you turn it on together, and then it is shown on the kid’s iPhone.

What happens technically

The parent and kid iPhones are paired once, side by side — like an Apple Watch: both show the same 6-digit code. From that, keys are derived that only these two devices know. Rules, requests and approvals are encrypted with them; Apple only carries them. The kid’s iPhone enforces the rules itself, even without a network and with the app closed, and sends a heartbeat after every 15 minutes of use — you set the interval. If it stays silent longer than the time you set, your iPhone warns you (“suspicious”); after 24 hours it counts as “lost”.

Apps are blocked on the kid’s iPhone through Apple’s Screen Time; the websites of well-known services additionally at network level, so the detour through the browser doesn’t work. A second parent’s iPhone pairs with the kid’s iPhone, behind your PIN. When one parent decides, the other sees who it was.

Platform

iPhone, iOS 17+

Requirement

Child account in Family Sharing

Blocking

Apple Screen Time (Family Controls)

Rules

Schedules · Daily limits · If-then · Places

Pairing

Side by side, 6-digit code

Encryption

Curve25519 · ChaChaPoly

Delivery

Directly when nearby, otherwise your iCloud

Our servers

none

Where the line is

The technology is the smaller problem. The bigger question is when you need a tool like this at all, and when an honest sentence at the kitchen table does more. familydevice is meant to enable the conversation, not replace it.

Built in Karlsruhe, Baden-Württemberg.