Comparison

Smithsonian vs PDF Book Read

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

Head to head
About

Smithsonian

Explore the solar system with interactive games and animations. Learn fascinating facts about planets, moons, and the asteroid belt. Designed for curious young minds to introduce astronomy basics.

Highlights
  • Fascinating facts about the solar system
  • Mini games like Space Winter Rush
  • Interactive activities
  • Educational animations
  • Read to Me text
  • Collect planet badges
Features
Read full description

Join us on an exciting voyage through the solar system! Play, touch, read. and learn facts about the 8 planets in our solar system in this new app from The ©Smithsonian and PlayDate Digital. Designed for curious minds, this app features brilliantly illustrated animations which are sure to engage and entertain. Why is Mars called the Red Planet? Which is the brightest Planet? How many moons does Neptune have? What is the Asteroid Belt? Explore Planets, learn facts, and play games as you rocket through the solar system. Your space enthusiast will love learning all about the wonders of space and the universe. The mini games reinforce the learnings and interactive activities will keep kids engaged. Features: • Lots of fascinating facts about our solar system, its planets, and more! • Featuring mini games including Space Winter Rush, Comet Ceasefire, Solar System Sorting, Gas Planets and more! • Over 10 other interactive activities related to your space adventure. • Educational content and animations will entertain and engage while teaching simple astronomy basics. • ‘Read to Me’ text • Collect solar system and planet badges as you complete each level Planets and the Solar System from ©Smithsonian Kids is designed to deliver on these Learning Goals: • STEM: Introduce young learners to astronomy and science methods. • STEM: Expand young learners' curiosity and knowledge of the world around them. • Counting and Quantifying: Identify and organize groups of objects logically. • Visual Discrimination: Distinguish between different shapes, sizes, colors. • Visual Memory: Remembering and recalling visual information. • Color Recognition and Differentiation: Identifying and naming colors. • Shape Recognition and Classification: Identifying objects based on different shapes. ABOUT THE SMITHSONIAN The ©Smithsonian is the world’s largest museum and research complex, dedicated to public education, national service, and scholarship in the arts, ©Smithsonian sciences, and history. The name of the ©Smithsonian Institution and the sunburst logo are registered trademarks of the ©Smithsonian Institution. For more information, please visit www.si.edu ABOUT PLAYDATE DIGITAL PlayDate Digital Inc. is a publisher of high-quality, interactive, mobile educational software for children. PlayDate Digital's products nurture children's emerging literacy and creativity skills by turning digital screens into engaging experiences. PlayDate Digital content is built in partnership with some of the world's most trusted global brands for kids. Visit us: playdatedigital.com Like us: facebook.com/playdatedigital Follow us: @playdatedigital Watch all our app trailers: youtube.com/PlayDateDigital1 HAVE QUESTIONS? We'd love to hear from you! Your questions suggestions and comments are always welcome. Contact us 24/7 at info@playdatedigital.com

About

PDF Book Read

Features
Read full description

Reading documents in a foreign language doesn't have to be hard. VocabPDF is the ultimate PDF reader designed specifically for language learners, students, and professionals. Stop switching between your document and a dictionary app. With VocabPDF, you can read any PDF, tap on unknown words to translate them instantly, and save them to your personal vocabulary list with a single tap. KEY FEATURES: • Smart PDF Reader: Smooth, fast, and optimized for reading text-heavy documents. • One-Tap Translation: Instantly translate words to your device's native language. • Highlight & Save: Mark important words with beautiful neon colors and save them with their context sentences. • Spaced Repetition System (SRS): Review your saved words effectively and move them to your long-term memory. • Text-to-Speech: Listen to the correct pronunciation of any word. VOCABPDF PREMIUM: Upgrade to Premium to unlock the full potential of your learning! • Unlimited Word Saves: Break the 50-word limit and build an endless vocabulary library. • Unlimited SRS Reviews: Master as many words as you want, anytime. Whether you are studying for exams like TOEIC, TOEFL, or IELTS, reading academic papers, or just enjoying a foreign book, VocabPDF is your perfect reading companion. Download now and start building your vocabulary today! Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

Screenshots

Smithsonian4 screens
PDF Book Read4 screens

Verdict

The call

The clearest difference is update cadence: PDF Book Read at every 2 weeks against Smithsonian's every 3 months. Smithsonian's advantage is iOS requirement (13.0 vs 26.2). On price, ads, in-app purchases 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. Smithsonian sells 2 one-off in-app purchases and PDF Book Read sells 2 in-app purchases, starting at $1.99 per year. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

Smithsonian ships an update every 3 months, PDF Book Read every 2 weeks. The most recent releases landed on September 22, 2026 and September 13, 2026 respectively.

Scorecard2 real differences · 6 level
Smithsonian versus PDF Book Read: the parameters behind the verdict, then further details
ParameterSmithsonianPDF Book Read
PriceFreeFree
Positive reviews100.0% of reviews—
Update frequencyEvery 3 monthsEvery 2 weeks — better
AdsNoNo
In-app purchasesYesYes
MonetizationFree with in-app purchases—
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS13.0 — better26.2
Further details — not scored
Size285 MB9 MB
Age rating4+4+
DeveloperPlayDate DigitalYuya Takamoto

In-app purchases

2 purchases

Smithsonian

One-time2
  • Remove Ads$1.99
  • Buy 5 Planets$2.99
2 purchases

PDF Book Read

Subscriptions1
  • Annual Premium$1.991 Year
One-time1
  • Lifetime Premium$2.99

Questions

Is Smithsonian free?
Smithsonian is free to download, with in-app purchases available.
Is PDF Book Read free?
PDF Book Read is free to download, with in-app purchases available.
Do Smithsonian or PDF Book Read have ads?
Neither Smithsonian nor PDF Book Read shows ads.
Which is updated more often, Smithsonian or PDF Book Read?
Smithsonian ships an update every 3 months, and PDF Book Read every 2 weeks. Most recently, Smithsonian was updated on September 22, 2026 and PDF Book Read on September 13, 2026.

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