Comparison

Pearl Diver vs Comprehension Builder.

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

Head to head
About

Pearl Diver

Dive into the ocean to master the number line, including fractions and decimals, by collecting pearls. This educational game is designed by experts to align with Common Core standards for grades 3-8.

Highlights
  • Number line mastery
  • Fractions and decimals
  • Common Core alignment
  • Progress tracking
  • Educational game design
Features
Read full description

Throw on your diving helmet, and head into the depths of the sea! Master the number line, including fractions and decimals, while gathering beautiful pearls. Will you find the elusive black pearl? • Ideal for elementary and middle school students, grades 3-8. Developed by mathematics educators, researchers, and game developers at the Learning Games Lab at New Mexico State University. Games developed by the Learning Games Lab undergo a rigorous instructional design process, extensive user testing, and input from learners, teachers, and researchers. Pearl Diver addresses Common Core standards relevant to the number line and properties of numbers, including: • Understanding numbers, ways of representing numbers, and number systems. • Understanding and representing commonly used fractions. • Understanding fractions as part of unit wholes and as locations on number lines. • Comparing and ordering fractions, and finding their approximate locations on the number line. Read about research documenting learning effectiveness of Math Snacks: http://mathsnacks.com/research.html Pearl Diver was developed as part of the "Math Snacks" initiative. Other free animations, activities, and games are available through the Math Snacks web site at http://mathsnacks.org. Math Snack materials were developed with support from the National Science Foundation (0918794 & 1503507). Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. Some materials were originally prototyped or discussed as part of a cooperative agreement from the U.S. Department of Education (U295A050004).

About

Comprehension Builder.

This app helps users improve reading comprehension, working memory, and the ability to answer questions about text. It features incremental learning with texts that increase in length and difficulty as skills develop, along with a reward system for motivation. Designed for learners of all ages, including those with special needs or learning English.

Highlights
  • Passage comprehension practice
  • Working memory development
  • Answering multiple-choice questions
  • Incremental learning levels
  • Reward Center for motivation
  • 200+ fiction and non-fiction texts
  • Content designed by teachers
Features
Read full description

** Happy Frog Apps is a Mom’s Choice Award Winner! Also featured on FunEducationalApps.com, TeachersWithApps.com, and more! ** The “Comprehension Builder” app builds skills in passage comprehension, working memory and answering multiple choice questions about a text. What parents say about our awesome apps: *** 5 stars! Brilliant! An app that understands how kids actually learn. Thank you. *** 5 stars! Every one of your apps that I’ve tried is great! When using “Comprehension Builder”, your learner will first read a passage. The learner must then hold the information in memory in order to answer a multiple choice question. To build sustained attention and working memory, early levels contain 2-sentence texts with limited word count. As comprehension is demonstrated and memory increases, the texts increase in length and difficulty. “Comprehension Builder” contains 200+ fiction and non-fiction texts on a variety of topics. This app is perfect for learners who: - when reading or listening, information seems to ‘go in one ear and out the other.’ - have trouble responding to questions about a text unless they can refer back to the text. - can understand each sentence, but don’t seem to put them together to make meaning from the text as a whole. Additional Features: - Incremental learning. New levels are unlocked only when your child demonstrates mastery. - Fun and engaging Reward Center to increase motivation. - Contains over 600 questions, with content designed by professional teachers and researchers. Our apps are designed for and tested by typical and special needs children. Testers include children with Autism and other special needs. Our apps work for them! Our apps are also suitable for adults dealing with aphasia or learning English as a Second Language. To evaluate the app, download the free version, which has 2 free levels. The remaining levels accessed with an in-app purchase. If you prefer no in-app purchases, download the School Edition (SE) version of this app, which includes all levels and up to 10 users. We take customer service very seriously! If you ever have a problem or find that we've missed something, contact us at our website and we will do our best to fix the problem.  www.HappyFrogApps.com Our apps are safe for kids. We collect NO private information in our app. None! Our apps do not allow unrestricted web or social media access. We conform to the Children's Online Privacy Protection Act.

Screenshots

Pearl Diver4 screens
Comprehension Builder.4 screens

Verdict

The call

The clearest difference is review sentiment: Pearl Diver at 76% against Comprehension Builder.'s 0%. Pearl Diver also leads on rating (5.0 vs 2.0) and in-app purchases (none vs 3). Comprehension Builder.'s advantage is iOS requirement (12.2 vs 17.6). On price, ratings volume, 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

Both are free to download. Comprehension Builder. sells 3 one-off in-app purchases. Pearl Diver asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Pearl Diver holds the better App Store score, 5.0 against 2.0. Both are backed by a comparable volume of ratings — 2 and 2 respectively. Written reviews point the same way: 76% of Pearl Diver's written reviews are positive against 0% of Comprehension Builder.'s.

UpkeepUpdate frequency

Pearl Diver ships an update every 20 months, Comprehension Builder. every 47 months. The most recent releases landed on October 17, 2026 and October 16, 2026 respectively.

Scorecard6 real differences · 4 level
Pearl Diver versus Comprehension Builder.: the parameters behind the verdict, then further details
ParameterPearl DiverComprehension Builder.
PriceFreeFree
Rating5.0 (2 ratings) — better2.0 (2 ratings)
Positive reviews76.2% of reviews — better0.0% of reviews
Number of ratings22
Update frequencyEvery 20 months — betterEvery 47 months
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFree — betterFree with in-app purchases
DevicesiPhone, iPadiPhone, iPad, iPod — better
Requires iOS17.612.2 — better
Further details — not scored
Size28 MB50 MB
Age rating4+4+
DeveloperNew Mexico State University Board of RegentsJanine Toole

Customer experience

Pearl Diver

All ratings2 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews21 reviews
Positive76.2%
Neutral4.8%
Negative19.0%

Comprehension Builder.

All ratings2 ratings
Positive0.0%
Neutral50.0%
Negative50.0%
Written reviews2 reviews
Positive0.0%
Neutral50.0%
Negative50.0%

In-app purchases

None

Pearl Diver

No in-app purchases

3 purchases

Comprehension Builder.

One-time3
  • Two Users$1.99
  • All Levels$3.99
  • 10 Users$3.99

Questions

Is Pearl Diver free?
Pearl Diver is free to download, with no in-app purchases.
Is Comprehension Builder. free?
Comprehension Builder. is free to download, with in-app purchases available.
Which has better reviews, Pearl Diver or Comprehension Builder.?
Pearl Diver is rated higher. Pearl Diver averages 5.0 out of 5 from 2 ratings, while Comprehension Builder. averages 2.0 from 2 ratings.
Do Pearl Diver or Comprehension Builder. have ads?
Neither Pearl Diver nor Comprehension Builder. shows ads.
Which is updated more often, Pearl Diver or Comprehension Builder.?
Pearl Diver ships an update every 20 months, and Comprehension Builder. every 47 months. Most recently, Pearl Diver was updated on October 17, 2026 and Comprehension Builder. on October 16, 2026.

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