REDMARKER uses AI-powered OCR to scan and validate maths worksheets rapidly. See which answers are correct and which need practice, reducing homework checking time by 93%.
Every evening, parents, teachers and tutors spend countless hours checking heaps of junior maths homework by hand
45+ minutes per child, every evening checking 100+ problems across multiple worksheets
Manual checking is error-prone and takes away from teaching time
No easy way to track students' improvements over time
REDMARKER transforms homework checking from a 45-minute chore into a 3-minute task
"We now spend the reclaimed time actually HELPING our children understand their mistakes, not just hunting for wrong answers."
Everything you need to check homework faster and track student progress
Point your phone's camera at any worksheet. The app automatically detects and crops to the worksheet area for accurate results.
Powered by GPT-4o Vision, REDMARKER reads handwritten and printed maths problems, validating worksheets comprising addition, subtraction, multiplication, and division.
Automatically identify student names and class info. Worksheets are organised into folders by student or class.
Track improvement over time with visual accuracy charts. Identify which students need extra help.
Did the app misread something? Tap any result to manually correct the expression or answer. The app recalculates instantly.
Designed to work seamlessly with Kumon, Twinkl, and school worksheets. Handles various formats and layouts automatically.
See REDMARKER in action, screen by screen
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Point your camera at a maths worksheet. The app shows a capture box overlay. Tap to capture or use Smart Scan to capture multiple worksheets quickly.
REDMARKER uses GPT-4o Vision to read the worksheet, identify each problem, extract expressions and answers, then validate them automatically.
Worksheets are automatically organised by student name and class. Navigate folders to find specific worksheets.
View the worksheet with discrepancies highlighted. Pinch to zoom and pan. See an overlay table of all incorrect problems.
View detailed progress charts showing accuracy over time. See statistics, trends, and identify students who need extra help.
Manually correct results when the app misreads handwriting.
To delete a worksheet, swipe left on the worksheet then click Delete.
Select the result you want to update
Select and edit the expression or student's answer. The app recalculates automatically.
Worksheets without student information are placed in "Unidentified Students". Move them to existing student or class folders.
When moving a worksheet.
Filter by student, class, or date range. Click the filter button in the header.
View account status, subscription tier, remaining credits, and usage statistics.
Access settings from any screen via the Settings button.
Feedback from actual users
"REDMARKER has completely transformed our evening routine. I've become so reliant on this tool."
"As a teacher, I love how REDMARKER automatically organises worksheets by student. The progress tracking helps me identify which students need extra support, and I can spend more time teaching instead of grading."
"The AI is incredibly accurate, even with messy handwriting. The manual correction feature is perfect for those rare times when the app misreads something. This app is a game-changer for homework checking, and has already saved me tonnes of time."
Everything you need to know about REDMARKER
REDMARKER uses GPT-4o Vision, one of the most advanced AI models available. It accurately reads both handwritten and printed math problems with high precision. The app also includes a manual correction feature, so you can easily fix any rare errors if the app misreads handwriting.
Your photos are processed securely and are never stored on our servers. Images are temporarily sent to OpenAI's GPT-4o API for validation purposes only, then immediately deleted after processing. OpenAI does not use your images to train their models, and all data is handled according to their privacy policy. All worksheet data and images are stored locally on your device only. We take your privacy seriously and only share images with OpenAI's API as necessary for the validation of maths worksheets.
REDMARKER requires an internet connection to process worksheets using AI. However, once worksheets are processed, you can view results, track progress, and organise worksheets offline. The app also includes a background processing queue, so worksheets captured while offline will be processed automatically when you reconnect to the internet.
REDMARKER works on iOS 13.0 or later and Android 8.0 (API level 26) or later. The app is optimised for modern devices and takes advantage of the latest mobile technologies for the best performance and accuracy.
Yes! REDMARKER includes data export functionality. You can export your worksheets, progress data, and student information. Use the export feature in the app to share your data or create backups. All your data is stored locally on your device, so you have full control.
Credit top-ups are available when you exceed your monthly subscription limit. You can purchase credit packages (100, 250, or 600 worksheets) that are used automatically when you need them. Credits never expire, so you can use them whenever you need extra worksheets. This gives you flexibility without requiring a subscription upgrade. View credit packages →
REDMARKER offers a free tier with 10 worksheets per month, perfect for trying out the app. For regular use, Premium plans start at $9.99 per month for 200 worksheets, or $99.99 per year with 17% savings. If you need more worksheets, you can purchase credit top-ups (100, 250, or 600 worksheets) that never expire. View all pricing options →
No, you don't need to pay extra for future upgrades. All app updates, new features, and improvements are included with your subscription at no additional cost. Whether you're on the free tier or a Premium plan, you'll automatically receive all updates and new features as they're released. We're constantly improving REDMARKER based on user feedback, and these enhancements are always included in your plan.
Yes, we provide support for all users. If you encounter any technical issues or have questions, you can contact our support team directly through the app's Settings screen. We aim to respond to all support requests promptly and help resolve any issues you may experience. Your feedback is valuable to us, and we're committed to ensuring REDMARKER works smoothly for all users.
Yes, we're continuously working to expand worksheet format support. Currently, REDMARKER works excellently with Kumon and Twinkl worksheets, as well as various custom worksheet layouts including 2-column lists, bordered tables, and grid formats. We're actively developing support for additional formats and welcome suggestions from users. All format updates are included with your subscription at no extra cost.
Check homework quickly and spend more time helping your kids learn
Mark worksheets faster and track student progress effortlessly
Monitor improvement over time and identify areas needing practice
Organise and track multiple students' work in one place
Start free with 10 worksheets/month, or upgrade to Premium for 200 worksheets/month
10 worksheets per month
All core features included
200 worksheets per month
Everything in Free + Priority support
View Full PricingCredit packages available
Purchase credits when you exceed your limit
View Credit PackagesAll plans include the same powerful features. Upgrade anytime or purchase credit top-ups when you exceed your monthly limit. See full pricing details →
We take your data privacy seriously
All worksheet images and student data are stored locally on your device. We never store your images or personal information on our servers. Your data stays in your control.
Images are processed securely through encrypted connections and immediately deleted after processing. We use industry-standard encryption to protect your data in transit.
We comply with GDPR and other data protection regulations. You have full control over your data with export and deletion features. View our Privacy Policy →
Your data, your control. All worksheet images and student information are stored exclusively on your device. We only store minimal metadata (subscription tier, usage counts) associated with an anonymous token, never personal information.
Download REDMARKER today and transform how you check homework
Available now on iOS and Android