Stop copying answers. Find your mistake.

Write on your homework with Apple Pencil. Tap Check and the coach circles your first mistake and explains it, right on the page.

You're on the list. We'll email you the link to open on your iPad.

Free while we test on real iPads. No card needed. The first round is a small group of testers 18 and older in the US, on an invite code.

In a study of about 1,000 high schoolers, plain AI help cut later test scores 17%. A tutor that guided them instead of handing over answers mostly fixed that. Bastani et al., PNAS 2025

Real coach, sped up. A recording of the app played fast: his writing at 2 to 3x, the waits cut short, the coach's own moves at 1.25x. The writing is scripted; the reading, circles, notes and the quiz are the real coach.

Screen recording of Pencil Coach on an iPad, real coach, sped up (his writing at 2 to 3x, the waits cut short, the coach's moves at 1.25x). He writes 3x + 5 = 20, then 3x = 25, then x = 25 over 3, and taps Check. The coach circles 3x = 25 and writes: Take 5 away from both sides instead. He fixes the line to 3x = 15 and checks again: That works now, and it circles the next line. Then he asks for a quick quiz and it writes three equations on his page. Last, on a homework PDF he asks how to think about question 1 and the hint appears right on the PDF.

How it works

  1. Handwriting on lined paper: 3x + 5 = 20, then 3x = 25, then x = 25/3.

    Write.

    On a blank page or your homework PDF. Math or code.

  2. After tapping Check: the coach's cursor reads down his lines with a Reading tag, and the bar says The coach is reading.

    Tap Check, or just ask.

    "How should I think about this?" works out loud too.

  3. The line 3x = 25 circled in orange with the coach's handwritten note: Take 5 away from both sides instead. Below, it explains that the 5 went onto the 20 and asks what is left on the right.

    Fix it yourself.

    It says what went wrong and what to do next. Stuck? It writes the setup, draws it out, or shows a similar example. The answer only if you ask.

Copying gets the homework done.
Understanding gets the test done.

What you get

The mistake gets circled where you wrote it.

Not in a chat window you have to read back and forth from.

A homework PDF, Practice Test 3. Under question 1 the student wrote 3x = 25; the coach circled it in orange and wrote beside it in its handwriting: Take 5 away from both sides.

It explains. You solve.

It says what went wrong and why, draws it out, and shows a similar example when you ask. You still write the answer.

The Show me how card: a worked example on a similar problem, nums = [1, 4, 6] with target 10, in indented Python, played step by step. This step shows i = 0, j = 1 and says: The if adds the number at i to the number at j, two different spots.

It tells you what it read.

Every hint says what it read off your page. If it read you wrong, tap and fix it; when it isn't sure, it asks first.

The Rebuild list of saved mistakes. Each row shows the circled line, the coach's note and what it read, for example Add 4 to both sides instead, read: 2x = 6.

Math and code.

Handwrite a LeetCode loop the same way you'd handwrite algebra.

Handwritten Python for Two Sum, set as a clean code block. Three lines have green ticks and the line if nums[i] + nums[i] == 9 is circled with the note: Right now this adds the same number to itself. The coach explains that the first pass checks 2 + 2 and that a pair needs two different spots in the list.

later test scores after plain AI help

What the research says

In a study of about 1,000 high schoolers, plain AI help cut later test scores 17%. A tutor that guided them instead of handing over answers mostly fixed that.

Bastani et al., PNAS 2025. Generative AI without guardrails can harm learning: Evidence from high school mathematics.

Free while we test

Beta

$0during the beta

Free while we test on real iPads. No payment is taken.

Join the iPad beta

Free

3Checks a day

Free stays free after the beta. No card needed.

Pro

$59.99a year

After the beta. A free 7 day trial on the yearly plan, or $9.99 a month. Up to 60 Checks a day.

Cancel in Settings in 2 taps.

Questions

Something else? Contact us.

Does it give me the answer?

Not by default. It shows where your work went wrong and explains why in plain words, and it can walk you through a similar example or a quick visual. If you clearly ask for the answer, it shows the step and why it works.

Can it read my handwriting?

It shows you what it read, and asks when it isn't sure. Neat print reads best today.

Does it work on my homework PDF?

Yes. Import the PDF, write on it, ask about any question.

Which iPads?

Any iPad with Safari and an Apple Pencil (1st gen, 2nd gen, USB-C, Pro). Finger works too, Pencil is better.

Is this cheating?

It's built to stop the copy and paste habit: no answer until you've tried. Your teacher sees your work, not ours.

What gets sent to the AI?

A picture of the page you're on and what you typed, only when you tap Check or ask. Nothing in the background.

How old do I need to be?

The app is for ages 13 and up. The first beta round is for adult testers, 18 and older, in the US.

Does it do coding?

Yes. Python and LeetCode style problems, handwritten.

What happens after the beta?

Free stays at 3 Checks a day. Pro is $59.99 a year or $9.99 a month.

Stop copying answers. Find your mistake.

You're on the list. We'll email you the link to open on your iPad.

Free while we test on real iPads. No card needed. The first round is a small group of testers 18 and older in the US, on an invite code.