Updated 3 November 2026 by Spencer Lay, who makes FocusFlow.
How they differ
Every blocker on iPhone uses the same Apple Screen Time system underneath. What differs is what it takes to get back in: waiting, tapping, a schedule ending, a physical device, or finished work.
We make FocusFlow, so read the descriptions below with that in mind. They describe how each app works, not prices, which change often. Check the App Store before you pay for anything.
FocusFlow
Apps stay locked until you finish a task you set and prove it with a photo, which an AI model checks. Each task earns 15 minutes by default. Built by a college student for homework, with blockout times for class and bedtime, daily caps, and tasks from your calendar, Reminders or Canvas. Free to download.
Opal
Blocks apps on a schedule or during focus sessions, with a strict mode that is hard to end early. Good if your problem is time of day rather than unfinished work.
one sec
Puts a short pause, like a breathing exercise, in front of an app when you open it. It slows you down rather than locking you out, which suits habit-checking more than deadlines.
ScreenZen
Also adds a delay before an app opens, with options to make the wait longer and to set limits and schedules.
Forest
You plant a virtual tree that grows while you stay off your phone and withers if you leave. A gentle, game-like nudge, with an optional mode that blocks apps during a session.
Brick
A small physical device. You tap your phone against it to lock your chosen apps, and tap again to unlock, so the way back in is wherever you left the Brick.
Apple Screen Time
Built into every iPhone. Downtime and App Limits block apps on a schedule or after a set time. On your own phone, "Ignore Limit" is one tap away, so it works best set up by someone else with a passcode.
| App | How you get back in | Best for |
|---|---|---|
| FocusFlow | Finish a task and send a photo | Getting homework done first |
| Opal | A schedule or session ends | Blocking set hours |
| one sec | Wait through a short pause | Breaking reflex opens |
| ScreenZen | Wait through a delay | Breaking reflex opens |
| Forest | End the focus session | Short, timed study blocks |
| Brick | Tap the physical device | Leaving the phone locked for hours |
| Apple Screen Time | Limit or schedule ends, or Ignore Limit | Parents setting limits with a passcode |