Readability vs Cosmo (formerly ClassUp)
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Readability
This app uses AI-powered voice technology to provide personalized reading tutoring for children. It listens as kids read aloud, offers pronunciation correction, and assesses comprehension through interactive questions. The app also builds vocabulary and allows parents to track progress.
- AI-powered voice recognition for reading practice
- Real-time pronunciation correction
- Interactive voice-based comprehension questions
- Personalized vocabulary lists
- Parent dashboard for progress tracking
- Engaging grade-level stories with illustrations
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Readability’s award-winning Smart Reading & Comprehension Learning App gives your child the effectiveness of 1-on-1 tutoring. Our breakthrough voice-based technology LISTENS while your child READS, highlighting, and correcting any problem words. Kids from kindergarten to 6th grade will improve their reading, vocabulary, and comprehension skills all in the convenience of a mobile app. IMPROVE READING WITH 1-ON-1 TUTORING Readability prompts your child to read aloud and listens while providing reading help and real-time pronunciation correction as your child reads. If they get stuck, they can tap on the speaker icon to have Readability read the selected passage or word aloud. Readability automatically selects the right reading material for each child to maximize improvement and minimize the reading struggle. Your child will be eager to learn as these fun and educational grade-level stories come to life with bright illustrations. IMPROVE CRITICAL THINKING SKILLS Our industry-first comprehension with Interactive Voice-based Questions & Answers (IVQA™) asks your child questions verbally about the story they just read to improve their critical thinking skills. Your child then is prompted to answer the question verbally to ensure they fully understand what they read. Comprehension is as important as reading fluency, we deliver both in our smart reading app for kids. IMPROVE VOCABULARY Readability makes it easy to learn new words and their meaning with a personalized vocabulary list for your child. Your child can long-press on any word while reading to learn its pronunciation, meaning, and add it to their vocabulary list. Their vocabulary list is neatly organized A-Z and by book to further practice, review, and perfect new or difficult words. SET AND TRACK READING GOALS Set goals and follow your child’s progress with your very own Parent Dashboard detailing what they have read, reading duration, accuracy, comprehension, and speed. It also provides daily and weekly reading reports for accountability that can be shared with a teacher. ENGAGING BOOKS A massive selection of age-appropriate stories and educational works keep kids engaged and learning. Readability is the perfect reading app for kids. Getting started is easy with a 30-day free trial. Just download the app to sign up for your free trial. Cancel anytime. SUBSCRIPTION TERMS To access all app features, please subscribe to the 30-day free trial. Your subscription automatically renews unless auto-renew is turned off at least 24-hours before the end of the current period. Your account will automatically be charged at the subscription price for renewal, within 24-hours prior to the end of the current billing period. You can manage your subscription and/or turn off auto-renewal by visiting your Account Settings after purchase. • Visit https://www.readabilitytutor.com/payment-policy/ for payment terms • Visit https://www.readabilitytutor.com/terms-of-use/ for terms of use Copyright 2023 Readability
Cosmo (formerly ClassUp)
This app offers AI-powered, personalized learning experiences guided by real teachers. It provides live 1-on-1 classes, instant homework help, and adaptive learning plans to foster confident and motivated learners.
- Live 1-on-1 classes with AI and human teachers
- AI-powered personalized learning plans
- Instant homework help and chat support
- AI writing tool for assignments
- Unlimited practice for Math & ELA
- Progress tracking dashboard
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Becoming a confident thinker. A curious problem-solver. A joyful, motivated learner who’s ready for whatever the future holds. We’re a future-ready education system—powered by AI, guided by real teachers, and built for how children actually grow. 1. Live 1-on-1 Classes: Human Teachers + Smart AI In every session, real teachers and AI collaborate to create dynamic lessons that drive progress. Our virtual classrooms include interactive tools (whiteboards, quizzes!) to boost engagement. 2. Pick Your Favorite Teacher (or Let Us Choose!) Our experts match students with teachers based on learning style and goals—or you can directly select your preferred instructor from our verified educators. 3. Flex Scheduling: Learn Anytime, Anywhere Book classes 24/7 from your couch, library, or even soccer practice. Reschedule freely with xx-hour notice. 4. Cosmo: The AI Study Buddy Who Gets It 4.1 AI-Powered Personalized Learning Plans Customized weekly roadmaps adapting to your child’s pace and progress. 4.2 Instant Homework Help & Chat "Hey Cosmo, explain algebra!" Get step-by-step solutions, class bookings, or a pep talk with meme reactions. 4.3 AI Writing Tool Snap a photo of writing assignments for: Grammar fixes, Style suggestions, "Aha!" revision tips 4.4 Unlimited Practice for Math & ELA Enjoy endless questions and instant feedback—perfect for all skill levels. Learn anytime, anywhere! 4.5 Progress Tracking Dashboard Track mastered skills and growth areas with color-coded reports updated monthly.
Screenshots
Verdict
The clearest difference is monetization model: Cosmo (formerly ClassUp) at free with in-app purchases against Readability's subscription. Cosmo (formerly ClassUp) also leads on review sentiment (80% vs 56%). Readability's advantage is ratings volume (24K vs 879) and chart position (#196 vs unranked). On price, rating, update cadence and ads there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Readability sells 2 in-app purchases, starting at $19.99 per month and Cosmo (formerly ClassUp) sells 3 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.
On the App Store both sit at effectively the same score — 4.6 for Readability against 4.5 for Cosmo (formerly ClassUp). That said, the two scores are not equally well evidenced: Readability has 24K ratings behind it against 879, so its average is the more settled of the two. Written reviews are what separate them: 56% of Readability's written reviews are positive against 80% of Cosmo (formerly ClassUp)'s.
Readability ships an update fortnightly, Cosmo (formerly ClassUp) every 9 days. Both last shipped on September 24, 2026.
| Parameter | Readability | Cosmo (formerly ClassUp) |
|---|---|---|
| Price | Free | Free |
| Rating | 4.6 (24K ratings) — better | 4.5 (879 ratings) |
| Positive reviews | 55.9% of reviews | 80.1% of reviews — better |
| Number of ratings | 24K — better | 879 |
| Update frequency | Fortnightly | Every 9 days — better |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Monetization | Subscription | Free with in-app purchases — better |
| Best chart rank | #196 — better | — |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 15.1 | 15.0 — better |
| Further details — not scored | ||
| Size | 264 MB | 408 MB |
| Age rating | 4+ | 4+ |
| Developer | e4site Inc. | Algorithm of Learning Inc. |
Customer experience
Readability
Cosmo (formerly ClassUp)
User reviews
Readability
From 24K App Store ratingsWhat we love
- 👍 Helpful for struggling readers
- 🚀 Improves reading fluency
- 💡 Engaging for kids
- 👍 Useful data and progress tracking
Room to improve
- 🐛 Voice recognition issues
- 🐛 Inaccurate comprehension tests
- 💰 Expensive subscription
- 🐛 Glitchy performance
Cosmo (formerly ClassUp)
From 879 App Store ratingsWhat we love
- 👍 Awesome teachers
- 🚀 Personalized learning
- 💡 Engaging and fun lessons
- 🚀 Flexible scheduling
- 👍 Knowledgeable and professional tutors
Room to improve
- 🐛 Scheduling issues and class cancellations
- 💰 Expensive pricing
- 🤯 Poor customer service and communication
- 🐛 Technical issues with app and connectivity
Bugs and requests
Readability
Reported bugs
4 issues- App charges for free trial
- Subscription cancellation issues
- Inconsistent app behavior
- Compatibility problems on some devices
Requested features
4 requests- More customization options for text and background
- Improved voice recognition accuracy
- Expanded book selection
- Better comprehension testing
Cosmo (formerly ClassUp)
Reported bugs
3 issues- Frequent class cancellations
- Billing and refund issues
- Unreliable internet connectivity during classes
Requested features
4 requests- More affordable pricing options
- Improved scheduling and class management
- Better communication with parents
- Enhanced technical stability and reliability
In-app purchases
Readability
- Readability Tutor1 Month trial$19.991 Month
- Readability Tutor Annual1 Month trial$139.991 Year
Cosmo (formerly ClassUp)
- First Class$0.99
- Test 20 lessons package$0.99
- 3 one-on-one classes$74.99
Questions
Is Readability free?
Is Cosmo (formerly ClassUp) free?
Which has better reviews, Readability or Cosmo (formerly ClassUp)?
Do Readability or Cosmo (formerly ClassUp) have ads?
Which is updated more often, Readability or Cosmo (formerly ClassUp)?
Other comparisons















