Free on the App Store

You're already managing everything else. Why not your mental bandwidth?

You make 35,000 decisions a day.
Most of them are invisible.

ThinkLeft gives you a live readout of your mental energy — so you act when it counts and rest before you crash.

Free forever On-device, no account Pro available

Download for iOS See how it works

Fatigue Score

● Fresh — Make the hard calls

Decisions 50%

Time of day 20%

Peak

Restlessness 15%

Calm

App switching 15%

Focused

+ Log a Decision

The science behind it

Your "ThinkLeft" runs out of fuel. Here's what happens next.

The left prefrontal cortex is the engine behind careful thinking, self-control, and good judgment. Researchers call its depletion ego depletion — the more decisions you make, the less fuel is available for the next one. Thoughtful reasoning degrades into impulse, avoidance, and fog — often without you noticing.

Judges give harsher sentences at the end of the day. Doctors over-prescribe. Investors make riskier bets. You choose the easy option over the right one.

Most apps want more of your attention. ThinkLeft helps you protect it.

😶‍🌫️

Mental fog hits unexpectedly

You can't tell if you're tired or just overwhelmed until it's too late

🛒

You default to easy, not right

Impulse purchases, skipped workouts, regretted replies — all after a heavy decision day

😤

Small things trigger big reactions

A depleted brain has no buffer — patience runs out before the day does

🔁

You keep repeating the same patterns

Without data, you can't see when or why you burn out — so it keeps happening

What's inside

The first app that warns you before you make a bad call

Four science-backed signals feed one live score from 0–100. Your phone already knows when you're depleted — ThinkLeft finally tells you.

0–30

Fresh

Make the hard calls now

30–60

Warming

You're still sharp

60–80

Fatigued

Defer what you can

80+

Depleted

Rest, don't decide

Delay Mode

Try to log a major decision while depleted? ThinkLeft starts a 60-second timer (120s for critical calls) — a built-in cooldown that's saved more bad decisions than any productivity app ever has.

Flagship feature

Decision Window Advisor

Predicts exactly when your fatigue will hit each level — so you can schedule the meeting that matters during your sharpest hour, not your most depleted one.

Time-of-Day Awareness

Adapts to night-shift workers and early birds. The model learns your wake hour and adjusts — no rigid 9-to-5 assumptions.

HealthKit Sleep Sync

Auto-imports your sleep from the Health app. Bad night's rest? Your starting score reflects it — no manual logging required.

Personal Baseline

Calibrates to your normal — not a stranger's. Two weeks in, the score reflects how your brain actually behaves, not a generic average.

Weekly Digest

Every Sunday: your peak hours, your worst drains, the patterns you'd never spot on your own. Learn the version of yourself that exists in the data.

Home Screen Widget

Your live fatigue score, right on your home screen. Tap to log a decision in one move — no app launch required.

iCloud Sync

Optional and private. Sign in with Apple, and your history follows you across devices. Skip it and stay 100% on-device — your call.

Streaks & XP

Build self-awareness streaks, earn XP for consistent logging, and level up as you develop sustainable decision habits.

The process

From overwhelmed to in control — in three steps

Log decisions in 3 seconds

Tap the widget on your home screen, pick a weight (Quick · Major · Critical), done. ThinkLeft handles the rest in the background — time of day, restlessness, app switching — no manual tracking needed.

Your score updates live

Four signals feed one number from 0–100. Watch yourself move through Fresh → Warming → Fatigued → Depleted as the day unfolds. The Decision Window Advisor predicts when you'll hit each level.

Delay Mode catches your worst calls

Try to log a Major or Critical decision while depleted? A 60-second cooldown kicks in (120s for Critical). Just enough time to ask: "Am I deciding this, or is my exhausted brain deciding for me?"

See it in action

Four screens. The whole story.

Every feature, exactly as it appears on your iPhone.

Delay Mode 60-second countdown screen — **Delay Mode** The 60-second cooldown that catches your worst calls.

Decision Window Advisor showing predicted fatigue curve — **Decision Window Advisor** Predicts when you'll hit each fatigue level next.

Home screen widget showing live fatigue score — **Home Screen Widget** Tap to log a decision in one move — no app launch needed.

Privacy by design

The only app tracking your mind that doesn't actually track you.

Most "wellness" apps demand an account before you've even seen the screen. ThinkLeft does the opposite: it works fully on-device, no account, no upload. Sign in only if you want it to.

100% on-device by default

Your decisions, mood, motion, and score never leave your iPhone. No servers, no analytics, no profile.

iCloud sync is optional & anonymous

Want it on your iPad too? Sign in with Apple — no email, no password, no tracking ID. Your real identity stays with Apple, not us.

Zero ads. Zero data sales. Ever.

ThinkLeft makes money from Pro subscriptions — full stop. Your mental energy data is not the product.

You won't see this until your first decision is logged

Want this on your other devices?

Maybe later

The hidden cost

You're already managing everything else. Why not your mental bandwidth?

Make your most important decisions when your mind is clearest
Recognize the patterns that drain you before they repeat
Stop mistaking depletion for laziness or weakness
Build sustainable habits backed by real data about your own mind

The quality of decisions made late in the day is dramatically lower than those made in the morning — regardless of how smart or experienced you are.

— Based on research by Shai Danziger et al., PNAS 2011

Pricing

Free forever. Pro when you're ready.

The full fatigue score, decision logging, and Delay Mode are free forever. Pro unlocks the deeper insights once you're hooked.

Free

$0 forever

Everything you need to start beating decision fatigue today.

Live fatigue score (0–100)
Decision logging
Delay Mode protection
Home screen widget
100% on-device, no account

Download free

You make 35,000 decisions a day.Most of them are invisible.

Your "ThinkLeft" runs out of fuel. Here's what happens next.

The first app that warns you before you make a bad call

Delay Mode

Decision Window Advisor

Time-of-Day Awareness

HealthKit Sleep Sync

Personal Baseline

Weekly Digest

Home Screen Widget

iCloud Sync

Streaks & XP

From overwhelmed to in control — in three steps

Log decisions in 3 seconds

Your score updates live

Delay Mode catches your worst calls

Four screens. The whole story.

The only app tracking your mind that doesn't actually track you.

Want this on your other devices?

You're already managing everything else. Why not your mental bandwidth?

Free forever. Pro when you're ready.

Your brain deserves better data.

You make 35,000 decisions a day.
Most of them are invisible.