Homework help for iPhone, iPad, and Mac
Every step, not just the answer.
Capture a math or science problem from your Mac screen, a photo or the keyboard. Stemulus sends back a step-by-step solution with properly rendered math, then helps you turn the problems you save into study guides and practice rounds.
Coming soon to the App Store
For iPhone, iPad, and Mac. Not yet available to download.
10 free scan credits to start. No sign-in needed.
Algebra
Solve for x: 3x + 6 = 21
- Subtract 6 from both sides 3x = 15 Keep the equation balanced by subtracting the same amount from each side.
- Divide both sides by 3 x = 5 Divide 3x = 15 by 3 to leave x on its own.
- Check your answer 3(5) + 6 = 21 Substituting 5 into the original equation gives 21, as expected.
Solution
x = 5
Arithmetic checks passed
Adding a problem
Add a problem without retyping it.
However the problem reaches Stemulus, you see it first. Nothing is sent until you choose Check Problem, and capturing an image alone never uses a credit.
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Mac
Crop it straight off your screen
Press the capture shortcut, drag a box around one problem on any display, and it lands in a preview. The shortcut works while Stemulus is running, even with its window closed, and Capture Problem is also in the toolbar, the File menu and the menu bar.
Default shortcut ⇧⌘2, or choose ⇧⌘7 or ⇧⌘8 in Capture Settings. Esc cancels.
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iPhone and iPad
Photograph the page
Use the built-in camera, with flash for dim desks, or pick a photo you already took from your library.
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Any device
Type it, or drop it in
Write the problem out on any device. On the Mac you can also paste an image from the clipboard, choose an image file, or drag one onto the window.
What you get
A step-by-step solution you can follow.
Numbered steps, each with its reason
Every step has a title, the math for that step and a sentence on why it works, with equations typeset the way they look in a textbook.
An arithmetic check where one is possible
Supported calculations are checked by substituting the result back in. When a check cannot confirm the answer, the solution says to review it rather than pretending.
Your own answer, kept separately
Add the answer you got before you check. It is saved next to the solution, and viewing a solution never marks your attempt as correct.
Copy the LaTeX, share the solution
Copy the math as LaTeX for your notes, or share a summary of the solution with the system share sheet.
After the homework
From a pile of problems to a study set.
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01 · Assignments
Keep problems together
Group problems into assignments you can rename, archive or delete, and move problems between them later. Mark each one Got it, Review later or Still stuck, so you know what to come back to.
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02 · Study guide
A guide built from your own work
Generate a guide for an assignment: the concepts it covers, methods and formulas with when to use them, worked examples linked back to your original problems, and suggestions for what to review next with the evidence behind each one. Only checked, undisputed solutions are used as worked examples.
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03 · Practice
Three new questions, hints on request
Start a practice round and get three new questions drawn from the assignment, with topics you marked Still stuck or Review later first. Reveal hints one at a time, enter your attempt, then check it locally where the answer format allows, or ask for AI feedback. The worked answer stays hidden until you ask for it.
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04 · Again
Practice again for free
Saved guides and practice sets open for free and work offline. Practice the same set again as often as you like; only a new generation uses your allowance.
Honest by design
Built to help you learn, not just to get answers.
- AI-generated solutions can contain mistakes, and Stemulus says so next to every one.
- Revealing a worked answer does not count as getting it right. Practice summaries say what happened, such as two questions attempted and one answer matched, not a mastery score.
- Your review marks describe how you feel about a problem. They are never turned into a grade.
- Flag a practice question as wrong and it stops counting toward your results and review suggestions.
- Your assignments, guides and practice are stored on your device. There is no cross-device sync yet.
Pricing
Start free, then pay the way you study.
No sign-in is needed to check problems or subscribe. Every new account starts with 10 free scan credits. Link an Apple or Google account when you want to use your access on other platforms.
Subscription
Stemulus Pro
$4.99 per week
- 100 problem checks or study generations per rolling seven days
- Each check becomes available again seven days after you use it
- A failed generation returns its allowance
- Renews weekly until canceled
One-time purchase
50 Scan Credits
$2.99 once
- One credit checks one problem
- No subscription, buy another pack when you need it
- Opening saved solutions, guides and practice never uses a credit
US prices shown; your local price appears in the App Store before you buy. A problem check uses one scan credit. For people without a subscription, generating a study guide or practice set also uses one scan credit, disclosed before you confirm, and a failed generation returns it. The subscription renews automatically until canceled; manage or cancel it in your App Store account. No free trial is offered.
Coming to iPhone, iPad, and Mac.
Stemulus requires iOS 26.5, iPadOS 26.5, or macOS 26.5 or later, and is available in English.
Coming soon to the App Store
For iPhone, iPad, and Mac. Not yet available to download.