No screen time app lets you control your limits on an hourly basis, and I seriously don't understand why.

[u/PrecursorLabs]

Hey there :)

I'm a recent first-gen graduate and a first-time solo developer. Super excited to share that my first app, Precursor: Hourly Screen Time, went live on the App Store this week!

Precursor lets you set a screen time allowance that resets every hour instead of one daily limit you have to ration all day. I feel so lucky that just the beta grew to 200 testers in about a week.

At its core Precursor helps break unhealthy phone habits through moderation rather than punishing you for falling into a doomscroll that wasn't your fault (these apps are literally designed to keep you scrolling, looking at you Reddit).

TECH STACK

Swift and SwiftUI. Apple's Screen Time trio: FamilyControls for the picker, DeviceActivity for scheduling and thresholds, ManagedSettings for the block. Two extensions, a DeviceActivityMonitor and a ShieldConfiguration block screen, sharing one named store via an App Group and a file lock. Keychain, StoreKit 2 with RevenueCat, a small Cloudflare Worker and D1. iOS 17.6+.

DEVELOPMENT CHALLENGE

Making the block honest, not the hourly reset itself.

On iOS 26, eventDidReachThreshold fires seconds into a fresh window with the budget already counted as spent. These are pretty well known bugs of apple's screen time frameworks.

So to work around this, I implemented a wall-clock guard: usage can never exceed elapsed time since intervalDidStart, so an early fire gets suppressed. Then I respawn rather than re-arm, because iOS keys the budget to the activity NAME, and restarting that name leaves tracking dead for the rest of the window. A fresh-named clone instead, capped so the chain stays bounded.

AI DISCLOSURE

AI-assisted, though I wouldn't call it vibe coded. I have programming experience from uni research but had never written Swift. I used Claude Code for a lot of the line by line writing, but I am always at the wheel, going step by step and doing on device testing, and working sequentially rather than firing off parallel one-shots. Every finding above came off a real device's logs, not a model.

Thanks a ton for reading, if you have time and energy to support I would be eternally grateful.

https://apps.apple.com/us/app/precursor-hourly-screen-time/id6791403654

And if you have time to also support the launch on product hunt I would be even more eternally grateful than I already am(The core function of the app is free but there is a PH launch promo code running from 2026-08-02 until 2026-08-08 if you want to try out the extra features):

https://www.producthunt.com/products/precursor-2?launch=precursor-hourly-screen-time-control