Comparison

Sun to Moon Sleep Clock vs Readability

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

Head to head
About

Sun to Moon Sleep Clock

This app acts as a gentle sleep trainer for young children, visually indicating when it's time to stay in bed and when it's okay to wake up. It offers customizable features like sleep sounds, nap timers, and a reward system to encourage good sleep habits.

Highlights
  • Visual star countdown for bedtime
  • Customizable sleep and wake sounds
  • Nap timers and bedtime routine tools
  • Personalizable characters with outfits
  • Optional Snooze Rewards system
  • Visual shooting-star progress bar
  • PIN-protected settings
Features
Read full description

Sun to Moon Sleep Clock is a gentle sleep trainer that helps toddlers and young children learn when to stay in bed and when it’s okay to get up. Throughout the night, 26 stars disappear one by one, giving kids an easy visual countdown until morning. The app is quick to set up, fully customizable, and packed with optional sleep sounds, wake sounds, nap timers, and bedtime-routine tools. Kids can personalize the friendly Sun and Moon characters with outfits and accessories from their shops. Everything is unlocked from the start, but you can enable the optional Snooze Rewards system to encourage healthy sleep habits. The longer your child stays in bed, the more Snooze Coins they earn — and they can trade them for fun gifts for Sun and Moon. Wake-up times can be set from the settings screen or by tapping the orange time buttons on the main daytime screen. Tapping Goodnight triggers an instant sunset at bedtime. Need an early wake-up for a nap or a schedule change? Tap Moon’s nose three times for an out-of-schedule sunrise — and three more times for an immediate sunrise. Full instructions: https://www.msibley.com/sleep-clock Updates & tips: https://www.facebook.com/suntomoonsleepclock –––––––––––––––––––––––––––– Key Features • Gentle sleep training with a visual star countdown • Soothing sleep sounds: Fan, white noise (hair dryer), waves, heartbeat, whale song, rain and more — or silence • Fun wake-up sounds: Birds, digital alarm, drums, rooster, Happy Birthday, Santa/Jingle Bells and more — or silence • Custom schedules: Optional 7-day routine planner • Digital or analog clock styles, including a large-digit mode • Speaking Clock: Tap Sun or Moon’s mouth to hear the time (optional) • Customizable outfits and accessories for Sun and Moon • Themes: Birthday, Christmas, Easter, Halloween, St Patrick’s Day, Pirates, Sports, Space • Snooze Rewards system using collectible Snooze Coins (optional) • Shooting-star progress bar for nighttime visualization • Final Countdown Mode: Faster 12-star countdown before wake-up (optional) • Reading Time: Moon reads for up to an hour at sunrise or sunset • Nose Tap Naps: Set a nap duration and activate with 3 taps • Immediate Sunrise: Trigger instantly with 3 extra taps • Morning Memo: Write a message for your child — Sun can read it aloud (optional) • Dim & Auto-Dim controls to reduce brightness • Dark Mode for softer nighttime colors • Built-in help screens throughout the app • Multilingual support: English, German, Spanish, French, Italian, Dutch, Portuguese, Simplified Chinese, Japanese and Korean • PIN-protected settings with Face ID / Touch ID support (master code: 8529) • Dreamy illustrations by artist Michael Sibley –––––––––––––––––––––––––––– Helpful Notes • For uninterrupted use, enable Guided Access to disable device buttons • Keep your device plugged in while the app is running overnight • Reduce screen brightness or enable Auto-Dim for extended nighttime use • If you forget your settings PIN, the master code is 8529 –––––––––––––––––––––––––––– If You Find the App Helpful… A rating or review on the App Store really helps us improve Sun to Moon. Thank you for your support — and sweet dreams!

About

Readability

This app offers AI-powered reading assistance for children, acting like a personal tutor. It listens as kids read, provides real-time pronunciation correction, and enhances vocabulary and comprehension through interactive questions. Parents can track progress via a dashboard.

Highlights
  • AI-powered reading assistance
  • Real-time pronunciation correction
  • Interactive comprehension questions
  • Personalized vocabulary lists
  • Parent progress dashboard
  • Grade-level stories and books
Features
Read full description

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

Screenshots

Sun to Moon Sleep Clock4 screens
Readability4 screens

Verdict

The call

The clearest difference is price: Readability at Free against Sun to Moon Sleep Clock's $2.99. Readability also leads on ratings volume (26K vs 107) and update cadence (fortnightly vs every 2 months). Sun to Moon Sleep Clock's advantage is review sentiment (94% vs 55%) and in-app purchases (none vs 2). On rating, ads and device support 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

Readability is free to download; Sun to Moon Sleep Clock costs $2.99 up front. Readability sells 2 in-app purchases, starting at $19.99 per month. Sun to Moon Sleep Clock asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 4.5 for Sun to Moon Sleep Clock against 4.6 for Readability. That said, the two scores are not equally well evidenced: Readability has 26K ratings behind it against 107, so its average is the more settled of the two. Written reviews are what separate them: 94% of Sun to Moon Sleep Clock's written reviews are positive against 55% of Readability's.

UpkeepUpdate frequency

Sun to Moon Sleep Clock ships an update every 2 months, Readability fortnightly. The most recent releases landed on November 6, 2026 and November 11, 2026 respectively.

Scorecard8 real differences · 3 level
Sun to Moon Sleep Clock versus Readability: the parameters behind the verdict, then further details
ParameterSun to Moon Sleep ClockReadability
Price$2.99Free — better
Rating4.5 (107 ratings)4.6 (26K ratings) — better
Positive reviews94.1% of reviews — better55.3% of reviews
Number of ratings10726K — better
Update frequencyEvery 2 monthsFortnightly — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFree — betterFree with in-app purchases
Best chart rank—#175 — better
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS13.0 — better16.4
Further details — not scored
Size52 MB247 MB
Age rating4+4+
DeveloperMichael Sibleye4site Inc.

Customer experience

Sun to Moon Sleep Clock

All ratings107 ratings
Positive86.9%
Neutral4.7%
Negative8.4%
Written reviews17 reviews
Positive94.1%
Neutral5.9%
Negative0.0%

Readability

All ratings25,454 ratings
Positive90.5%
Neutral4.0%
Negative5.5%
Written reviews396 reviews
Positive55.3%
Neutral10.1%
Negative34.6%

Bugs and requests

Sun to Moon Sleep Clock

Not enough reviews yet to summarise bugs or 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

In-app purchases

None

Sun to Moon Sleep Clock

No in-app purchases

2 purchases

Readability

Subscriptions2
  • Readability Tutor1 Month trial$19.991 Month
  • Readability Tutor Annual1 Month trial$139.991 Year

Questions

Is Sun to Moon Sleep Clock free?
Sun to Moon Sleep Clock costs $2.99, with no in-app purchases.
Is Readability free?
Readability is free to download, with in-app purchases available.
Which has better reviews, Sun to Moon Sleep Clock or Readability?
Readability is rated higher. Sun to Moon Sleep Clock averages 4.5 out of 5 from 107 ratings, while Readability averages 4.6 from 26K ratings.
Do Sun to Moon Sleep Clock or Readability have ads?
Neither Sun to Moon Sleep Clock nor Readability shows ads.
Which is updated more often, Sun to Moon Sleep Clock or Readability?
Sun to Moon Sleep Clock ships an update every 2 months, and Readability fortnightly. Most recently, Sun to Moon Sleep Clock was updated on November 6, 2026 and Readability on November 11, 2026.

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