Comparison

Osmo Lettertopia 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

Osmo Lettertopia

This app transforms your tablet into a hands-on learning system for children aged 6-10. Players team up to build words, collect magical creatures, and boost spelling and social-emotional skills through collaborative play.

Highlights
  • Team-based word building
  • Collect magical creatures
  • Boost spelling skills
  • Develop social-emotional skills
  • Hands-on learning system
  • Collaborative play
Read full description

Move across the board by building words with letters and collect magical creatures as a team by matching descriptions! TEAM UP FOR EXCITING WORD BUILDING FUN! Boost spelling, word building and social-emotional skills. EXPLORE CORE LEARNING SUBJECTS THROUGH PLAY Designed for children ages 6-10 to build skills through fun collaborative play. TURN SCREEN TIME INTO LEARNING TIME Osmo’s unique technology transforms your tablet into a hands-on learning system! *Play your favourite Osmo Lettertopia on both iPhone and iPad! Use your iPhone with the Osmo Base for iPad and Words tiles - each can be found at playosmo.com. * Please see our device compatibility list here: https://support.playosmo.com/hc/articles/115010156067 *Requires the Osmo Base for iPad and Words tiles. Each sold separately or as part of Osmo Genius Starter Kit. Learn more by visiting www.playosmo.com. ABOUT OSMO -- 21ST CENTURY PLAY AND LEARNING Osmo combines healthy screen time and tangible play to make learning engaging and fun. Every Osmo game uses physical action and reflective artificial intelligence technology for digital learning in the real world. Help your child become more confident, thoughtful, and creative with Osmo.

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

Osmo Lettertopia4 screens
Night Zookeeper4 screens

Verdict

The call

The clearest difference is review sentiment: Night Zookeeper at 83% against Osmo Lettertopia's 6%. Night Zookeeper also leads on rating (4.6 vs 3.3) and ratings volume (613 vs 75). Osmo Lettertopia's advantage is monetization model (free with in-app purchases vs subscription). On price, update cadence, ads and in-app purchases 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. Osmo Lettertopia sells 2 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

Night Zookeeper holds the better App Store score, 4.6 against 3.3. That said, the two scores are not equally well evidenced: Night Zookeeper has 613 ratings behind it against 75, so its average is the more settled of the two. Written reviews point the same way: 6% of Osmo Lettertopia's written reviews are positive against 83% of Night Zookeeper's.

UpkeepUpdate frequency

Osmo Lettertopia ships an update every 3 months, Night Zookeeper every 2 months. The most recent releases landed on October 24, 2026 and October 27, 2026 respectively.

Scorecard4 real differences · 6 level
Osmo Lettertopia versus Night Zookeeper: the parameters behind the verdict, then further details
ParameterOsmo LettertopiaNight Zookeeper
PriceFreeFree
Rating3.3 (75 ratings)4.6 (613 ratings) — better
Positive reviews5.6% of reviews83.0% of reviews — better
Number of ratings75613 — better
Update frequencyEvery 3 monthsEvery 2 months — better
AdsNoNo
In-app purchasesYesYes
MonetizationFree with in-app purchases — betterSubscription
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS15.015.0
Further details — not scored
Size277 MB378 MB
Age rating4+4+
DeveloperTangible PlayWonky Star

Customer experience

Osmo Lettertopia

All ratings75 ratings
Positive56.0%
Neutral4.0%
Negative40.0%
Written reviews18 reviews
Positive5.6%
Neutral22.2%
Negative72.2%

Night Zookeeper

All ratings592 ratings
Positive90.5%
Neutral2.2%
Negative7.3%
Written reviews94 reviews
Positive83.0%
Neutral2.1%
Negative14.9%

Bugs and requests

Osmo Lettertopia

Not enough reviews yet to summarise bugs or requests.

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

2 purchases

Osmo Lettertopia

One-time2
  • 3-day trial of LettertopiaFree
  • Unlock Lettertopia$24.99
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 Osmo Lettertopia free?
Osmo Lettertopia 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, Osmo Lettertopia or Night Zookeeper?
Night Zookeeper is rated higher. Osmo Lettertopia averages 3.3 out of 5 from 75 ratings, while Night Zookeeper averages 4.6 from 613 ratings.
Do Osmo Lettertopia or Night Zookeeper have ads?
Neither Osmo Lettertopia nor Night Zookeeper shows ads.
Which is updated more often, Osmo Lettertopia or Night Zookeeper?
Osmo Lettertopia ships an update every 3 months, and Night Zookeeper every 2 months. Most recently, Osmo Lettertopia was updated on October 24, 2026 and Night Zookeeper on October 27, 2026.

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