Comparison

Cosmo (formerly ClassUp) vs Night Zookeeper

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

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.

Highlights
  • 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
Read full description

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.

About

Night Zookeeper

This app makes reading and writing fun for children aged 6-12. It offers mini-games, video lessons, and skill challenges covering a full English language arts curriculum. Children receive personalized feedback from tutors and earn rewards, while parents can track progress.

Highlights
  • Interactive mini-games
  • Video lessons
  • Skill challenges
  • Tutor feedback on writing
  • Parent progress tracking
  • Motivating rewards
  • Collaborative writing opportunities
Features
Read full description

The multi-award winning Night Zookeeper makes reading & writing fantastically fun and easy for 6-12 year olds. It’s trusted by thousands of parents around the world to improve their children’s spelling, grammar, reading & writing skills and really boost their confidence. The app has exciting mini games, video lessons, and skill challenges, created by educational experts and covering an entire english language arts curriculum. Children can play independently, and at their own pace, earning exciting and motivating rewards along the way. Tips from characters and inspiring prompts then help your child to write pieces of writing which our qualified tutors then read and give encouraging feedback on. This feedback can be viewed in your parent dashboard, where you can also track your child’s progress and achievements, and receive monthly printable resources. Alongside the thousands of learning activities and tutor feedback, a Night Zookeeper subscription provides your child with monthly awards, weekly writing competitions, and opportunities for collaborative writing in a safe, moderated environment. Night Zookeeper is: FUN: There are thousands of exciting and engaging activities for Grades 1 to 6. TRUSTED: An award winning program, used by thousands of families. Rated 4.7 on Trustpilot from 500+ reviews. COMPREHENSIVE: The program covers a full language arts curriculum of reading, writing, spelling, grammar & punctuation, that rewards children as they progress. SELF-PACED: Children can play independently and work through the program at their own pace. PERSONALIZED: Children get written feedback from our team of tutors on their pieces of writing- so you don't need to be the bad guy! SAFE: No in-app ads or purchases. TRACKABLE: A parent dashboard helps you to easily track your child's progress. OFFLINE & ONLINE: Free monthly printable resources are sent straight to your inbox. Users must log in with their account details to access Night Zookeeper. "There is nothing quite like Night Zookeeper, and I wish I had started them on it sooner!" Tim & Jennifer, parents "My kids were always frustrated with writing and reading, now they are excited each day and have started writing full stories." Justin, parent “My kids are loving this program and writing more than they ever have before. The game format and reward system holds their attention, and their creative juices keep flowing" Paul, parent Technical details: * Internet connection required Recommended: Latest iPad, Latest iPad Pro, Latest iPad Air, Latest iPad mini, Latest iOS Subscription options: The first 7 days of a subscription are free. Subscriptions renew automatically; your App Store account will be charged unless you cancel at least 24 hours before the end of the current period. Cancel anytime in your App Store account settings. Privacy Policy: https://www.nightzookeeper.com/privacy-policy Terms & Conditions: https://www.nightzookeeper.com/terms-and-conditions Start a FREE trial of Night Zookeeper today!

Screenshots

Cosmo (formerly ClassUp)4 screens
Night Zookeeper4 screens

Verdict

The call

The clearest difference is monetization model: Cosmo (formerly ClassUp) at free with in-app purchases against Night Zookeeper's subscription. Cosmo (formerly ClassUp) also leads on update cadence (every 9 days vs every 2 months). Night Zookeeper's advantage is iOS requirement (13.0 vs 15.0). On price, rating, review sentiment and ratings volume 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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Cosmo (formerly ClassUp) sells 3 one-off in-app purchases and Night Zookeeper sells 12 in-app purchases, starting at $14.99 per month. Whichever you choose, the download price is not the number that matters.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 4.5 for Cosmo (formerly ClassUp) against 4.6 for Night Zookeeper. Both are backed by a comparable volume of ratings — 879 and 536 respectively. Written reviews are what separate them: 80% of Cosmo (formerly ClassUp)'s written reviews are positive against 82% of Night Zookeeper's.

UpkeepUpdate frequency

Cosmo (formerly ClassUp) ships an update every 9 days, Night Zookeeper every 2 months. The most recent releases landed on September 28, 2026 and September 27, 2026 respectively.

Scorecard3 real differences · 7 level
Cosmo (formerly ClassUp) versus Night Zookeeper: the parameters behind the verdict, then further details
ParameterCosmo (formerly ClassUp)Night Zookeeper
PriceFreeFree
Rating4.5 (879 ratings)4.6 (536 ratings) — better
Positive reviews80.1% of reviews81.8% of reviews — better
Number of ratings879 — better536
Update frequencyEvery 9 days — betterEvery 2 months
AdsNoNo
In-app purchasesYesYes
MonetizationFree with in-app purchases — betterSubscription
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS15.013.0 — better
Further details — not scored
Size408 MB503 MB
Age rating4+4+
DeveloperAlgorithm of Learning Inc.Wonky Star

Customer experience

Cosmo (formerly ClassUp)

All ratings879 ratings
Positive86.1%
Neutral1.8%
Negative12.1%
Written reviews156 reviews
Positive80.1%
Neutral2.6%
Negative17.3%

Night Zookeeper

All ratings536 ratings
Positive90.5%
Neutral2.1%
Negative7.5%
Written reviews88 reviews
Positive81.8%
Neutral2.3%
Negative15.9%

User reviews

Cosmo (formerly ClassUp)

From 879 App Store ratings

What 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

Night Zookeeper

From 536 App Store ratings

What we love

  • 👍 Fun and engaging
  • 🚀 Helps improve writing skills
  • 💡 Gamifies learning
  • 👍 Motivates reluctant writers
  • 👍 Constructive feedback from tutors

Room to improve

  • 🐛 Glitchy and laggy performance
  • 🐛 Inconsistent difficulty levels
  • 🔋 Drains device battery
  • 🔒 Questionable subscription practices

Bugs and requests

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

Night Zookeeper

Reported bugs

3 issues
  • Freezing and crashing issues
  • Upside-down screen when creating new characters
  • Audio not working consistently

Requested features

3 requests
  • Dark mode option
  • Compatibility improvements for older devices
  • More content for older age groups

In-app purchases

3 purchases

Cosmo (formerly ClassUp)

One-time3
  • First Class$0.99
  • Test 20 lessons package$0.99
  • 3 one-on-one classes$74.99
12 purchases

Night Zookeeper

Subscriptions12
  • NZK 1 Month - 1 License7 Days trial$14.991 Month
  • 1 Month - 2 Licenses7 Days trial$17.991 Month
  • NZK 1 Month - 3 Licenses7 Days trial$17.991 Month
Show 9 more
  • 1 Month - 4 Licenses7 Days trial$21.991 Month
  • 3 Months - 1 License7 Days trial$36.993 Months
  • 3 Months - 2 Licenses7 Days trial$49.993 Months
  • 3 Months - 3 Licenses7 Days trial$49.993 Months
  • Yearly - 1 License7 Days trial$118.991 Year
  • Yearly - 2 Licenses7 Days trial$154.991 Year
  • Yearly - 3 Licenses7 Days trial$154.991 Year
  • Yearly - 4 Licenses7 Days trial$189.991 Year
  • Yearly - 5 Licenses7 Days trial$239.991 Year

Questions

Is Cosmo (formerly ClassUp) free?
Cosmo (formerly ClassUp) is free to download, with in-app purchases available.
Is Night Zookeeper free?
Night Zookeeper is free to download, with in-app purchases available.
Which has better reviews, Cosmo (formerly ClassUp) or Night Zookeeper?
Night Zookeeper is rated higher. Cosmo (formerly ClassUp) averages 4.5 out of 5 from 879 ratings, while Night Zookeeper averages 4.6 from 536 ratings.
Do Cosmo (formerly ClassUp) or Night Zookeeper have ads?
Neither Cosmo (formerly ClassUp) nor Night Zookeeper shows ads.
Which is updated more often, Cosmo (formerly ClassUp) or Night Zookeeper?
Cosmo (formerly ClassUp) ships an update every 9 days, and Night Zookeeper every 2 months. Most recently, Cosmo (formerly ClassUp) was updated on September 28, 2026 and Night Zookeeper on September 27, 2026.

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