AI study guide & practice generator · Available now on Android

Turn tonight's homework scans into tomorrow's quiz prep.

Most AI study guide generators expect you to upload 50-page lecture PDFs or type flashcards by hand. Stemulus builds custom study guides and three-question practice rounds directly from the math, physics, and chemistry homework problems you actually scanned.

iPhone, iPad, and Mac: coming soon to the App Store.

10 free scan credits to start. No sign-in needed.

Generated Practice Round · Calculus Derivatives

Practice Question 2 of 3 (from your Still stuck problems): Differentiate f(x) = (3x² + 1)⁴ with respect to x.

Progressive hints & check.

Hint 1: Identify the outer and inner functions u = 3x² + 1, f(u) = u⁴ Apply the chain rule: f'(x) = f'(u) · u'(x).
Hint 2: Differentiate each layer f'(u) = 4u³, u'(x) = 6x Use the power rule on both the outer power of 4 and the inner quadratic.
Multiply and substitute u back in f'(x) = 4(3x² + 1)³ · (6x) = 24x(3x² + 1)³ At x = 1, f'(1) = 24(1)(4)³ = 1536.

Worked Answer

f'(x) = 24x(3x² + 1)³

Arithmetic checks passed

Built for STEM retention

Study from the exact problems that tripped you up.

Generic flashcard decks don't teach you how to execute a multi-step math, physics, or chemistry problem. Stemulus closes the loop from homework check to active recall.

Assignments organized by mastery status

Group your scanned homework problems into named assignments (like "Chapter 4 Derivatives" or "Unit 3 Stoichiometry") and tag each problem Got it, Review later, or Still stuck.

Custom study guides tied to your own problems

Generate a study guide for any assignment covering key concepts, formulas and when to use them, worked examples linked back to your saved homework, and what to review next.

Three-question practice rounds with progressive hints

Generate three new practice questions prioritized from your Still stuck and Review later items. Reveal hints one at a time and check your own answer.

Honest self-grading & free offline access

Revealing a worked answer never counts as getting a practice question right. And once generated, every study guide and practice set opens offline for free.

What you can generate

One study loop for every quantitative course.

Generate study guides and practice rounds from your saved homework across math and science.

Study Guides

Concepts, Formula Rules & Linked Worked Examples

Automatically summarizes the core concepts in your assignment, lists the governing formulas and when each applies, and links worked examples directly back to your scanned problems.

Practice Rounds

3 Targeted Questions Prioritized by Difficulty

Draws from the problems in your assignment, prioritizing Still stuck and Review later, so you practice the exact skills you haven't mastered yet.

Offline Library

On-Device Storage with Zero Cost to Reopen

All saved solutions, study guides, and practice sets stay on your Android device and can be reopened anytime, on the bus or in a classroom, without spending a credit.

How the loop works

From first scan to exam day in four steps.

01 · 1. Scan

Check your homework problems step by step

Scan or type your math, physics, or chemistry homework using the Android camera scanner and review the numbered steps.
02 · 2. Tag

Save to an assignment and mark Still stuck

Add the problem to tonight's assignment and flag whether you Got it, want to Review later, or are Still stuck.
03 · 3. Summarize

Generate your assignment study guide

Create a structured formula and concept sheet built specifically from the problems inside that assignment.
04 · 4. Practice

Complete a 3-question practice round

Solve three new problems using progressive hints to test yourself before the quiz, without fake streaks or guilt notifications.

Why active practice beats passive review in math and science

In STEM courses, rereading notes or flipping through vocabulary flashcards rarely translates to higher exam scores. You only know whether you understand a kinematics equation, an acid-base titration, or a calculus derivative when you can set up and solve a fresh problem from scratch.

By building your study guide and practice questions directly from the homework problems you already scanned in the Homework Scanner App (whether from Geometry, Physics, Chemistry, or Algebra & Calculus), Stemulus eliminates busywork and focuses your practice time on the exact problem types where you marked Still stuck.

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 or Google Play 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 or in Google Play. No free trial is offered.

Questions & Answers

Frequently asked questions

Can I try the study guide and practice generator for free?

Yes. Every new user gets 10 free credits on Android with no sign-in required, and you can use your allowance to check problems or generate study guides and practice sets.

Does reopening a saved study guide or practice round cost a credit?

Never. Reopening saved solutions, study guides, and practice sets is completely free and works offline on your device.

What happens if a study guide or practice generation fails?

If a problem check or study generation fails due to a network or server error, your scan credit or weekly Pro allowance is automatically returned.

Does viewing the worked answer on a practice question count as a correct answer?

No. Stemulus keeps your score honest: revealing the worked answer lets you study the steps, but it does not count as getting the question right.

Available now on Android. Coming to iPhone, iPad, and Mac.

Stemulus requires Android 8.0 or later, or iOS 26.5, iPadOS 26.5, or macOS 26.5 or later, and is available in English.