GRE · SAT · TOEFL · IELTS

The vocab app that
blocks TikTok & Instagram until you study.

3,211+ words. Illustrated flashcards. Three vocab games. Spaced repetition. And the only app that turns your phone against your worst habits.

Start Your Free Trial
7 days free · $39.99/yr · Cancel anytime
GREGraduate school admissions958 wordsSATCollege admissions1,000 wordsTOEFLEnglish proficiency1,000 wordsIELTSInternational English955 words
3,211+ vocabulary words
4 standardized tests
3 vocabulary games
96× daily passive exposures
Now Live on iOS

Open TikTok?
Not until you study.

PrepLockin uses Apple’s official Screen Time API to block any app you choose. When you try to open it, a vocab quiz appears instead. Answer 5 questions. 90 seconds. Then scroll guilt-free.

  • You pick which apps to block
  • Uses Apple’s FamilyControls — not a hack
  • Your data never leaves your device
  • 5 questions, ~90 seconds to unlock
PrepLockin shield screen \u2014 Time to learn!

See it in action

Block distracting apps
Illustrated flashcards
3 vocabulary games
Match Madness game
Track your progress
Quiz mode
3,900+ words, one app

Three steps. Zero willpower.

1

Vocab finds you

Words rotate on your lock screen, home screen, and StandBy widget. You just glance at your phone — which you already do 96 times a day.

2

Earn your scroll

Pick the apps that steal your time. PrepLockin blocks them with Apple’s Screen Time API. A 5-question vocab quiz appears instead. 90 seconds and you’re free. Every unlock = 5 more words learned.

3

Play to remember

Three games encode each word three different ways. Match Madness, Word Scramble, Context Detective. Studying that feels like playing.

Everything you need.
Nothing you don’t.

3,211+ Illustrated Flashcards

Every word has a custom illustration. Visual + verbal = 65% better recall.

Wave System

10 words at a time. Master 8 to unlock the next wave.

Quiz-to-Unlock

Block Instagram, TikTok, Reddit — any app. A 5-question vocab quiz replaces the app until you pass. Uses Apple’s official Screen Time API.

Widgets Everywhere

Lock screen, home screen, StandBy. Words rotate every 30 minutes.

Spaced Repetition

Leitner system decides what you see and when. 3 correct = mastered.

Streaks & Heatmap

Daily streak counter + GitHub-style activity heatmap. Don’t break the chain.

Built on spaced repetition, dual coding theory, and the testing effect — proven to improve retention by 200%+

Questions

How does app blocking work on iOS?
PrepLockin uses Apple’s official FamilyControls framework — the same Screen Time technology built into every iPhone. You choose which apps to block. When you tap a blocked app, a branded shield appears with a 5-question vocab quiz. Answer correctly and the app unlocks. All data stays on your device.
Which tests does PrepLockin support?
PrepLockin supports GRE (958 words), SAT (1,000 words), TOEFL (1,000 words), and IELTS (955 words). Each test has its own curated word bank organized into progressive study blocks. Select your test during onboarding and switch anytime from Settings.
Can I study for multiple tests?
You select your primary study line during setup. You can switch between tests at any time from Settings. Your progress is tracked separately for each test.
What happens after the free trial?
Everything is fully unlocked during the 7-day trial. We send a reminder on Day 5. Cancel in iPhone Settings before Day 8 and you pay nothing.

Start today. Master your vocab by June 29, 2026.

Your test is getting closer.
Your vocabulary doesn’t have to fall behind.

Download on the App Store
7 days free · $39.99/yr or $7.99/mo · Cancel anytime