duoBooks: Language Learning app icon
Apple App StoreApp Store data

duoBooks: Language Learning

PlainProg LLCEducation4.69 · 48 ratings in United States
Open store
Publisher
PlainProg LLC
Category
Education
Version
7.1
Last updated
Sep 14, 2026
Public page · no login requiredUpdated Sep 27, 2026, 9:15 PM
Country
All countries combined
Store details come from the US App Store. Country figures describe that App Store, not where users live.
Period
7D30D
What we estimate
Downloads and revenue
Revenue is what users spend, before Apple's commission. These are estimates, not the developer's numbers.
Last updated
Sep 27, 2026, 9:15 PM
When we last checked this app.
Data quality
No estimate for this period yet
Not enough data yet.

Research answer

What AppTrendKit can say about duoBooks: Language Learning today

duoBooks: Language Learning has no estimate-backed download or gross-consumer-spend figure that meets the public evidence contract yet.

Observed App Store metadata, chart positions, and history are shown below. Missing, non-finite, undefined-currency, or undefined-metric evidence stays missing rather than becoming zero.

Performance

Downloads, revenue and chart history

Estimates for the last 7D. Chart positions come from the App Store; downloads and revenue are AppTrendKit estimates, shown as a size band (for example 10K–50K) with a confidence level.

Estimated downloads · 30D

Upper limit

Under 10K

Below the top 100 in Education (US)

The app is not in its category's top 100, so it has less than the app ranked #100 there. We show this limit until we have enough data for an estimate.

Estimated App Store gross consumer spend · 30D

Upper limit

Under $50K

Below the top 100 in Education (US)

The app is not in its category's top 100, so it has less than the app ranked #100 there. We show this limit until we have enough data for an estimate.

Revenue growth · 30D
—
Download growth · 30D
—
Grossing rank
—
Free rank
—

History

Collected daily performance

No daily history yet.

No backfilled days
Daily numbers appear after a few days of data.

Rank history

Chart positions

Lower rank is better. Only collected observations are shown.

No positive rank observations are stored for this storefront yet.

Coverage note

What the ranks mean

A missing rank is not treated as zero downloads or zero revenue. Apple chart feeds are bounded and may return censored or not-ranked observations outside the visible chart depth.

Read the method

Storefront mix

Top countries by estimated contribution · 7D

Country figures cover the days we collected in each country, so they don't add up to the worldwide estimate. Each country shows when it was last updated.

No 7D country-level economics have been persisted for this app yet.

Monetization

How the app makes money

Classification
Free listing
Price
Free
In-app purchases
—
Subscriptions
—

These are listing and product observations. They are not company revenue, subscriber counts, or advertising revenue.

App details

Store metadata

Version
7.1
Released
Nov 8, 2020
Last updated
Sep 14, 2026
Content rating
12+
Default storefront
US

Public IAP observations

Validated in-app purchase prices

Only persisted rows with an explicit public publication boundary are shown. Missing price, currency, country, or date values stay unknown.

Unavailable
No validated public IAP price observations have been persisted for this app yet.

Listing detail

What the store says

Read any book in any language with instant translation into your native language. We offer short stories designed specifically for beginner language learners. Alternatively, you can add any book from your device and read with translation whatever you want. Break any sentence into clear pieces and see every word explained in context. Instantly understand how the sentence works, what each word means, and how it fits into the full translation. In our app, you will also have your personal dictionary where you can keep your vocabulary in one place and easily review it whenever you want. Mastering correct pronunciation is key to language acquisition. In our app, you can listen to audio voiceovers of every sentence or word to hear it pronounced accurately. Immerse yourself in language learning with ease. To learn words, we provide a Spaced Repetition tool. With it you can review words at increasing intervals, ensuring long-term retention and mastery. Swipe through word flashcards effortlessly to build a robust vocabulary and make memorizing words a seamless part of your daily routine. Build your English vocabulary. Many people who are not native English speakers use our app as epub reader to read scientific materials or programming books in English. As long as you have an EPUB file for what you want to read, our app is the best choice. Our bilingual book reader is designed to enhance your language proficiency one page at a time. Practice and study foreign languages by reading parallel texts where every sentence is translated into your native language. Reading books with translation is a proven method for language learners to improve their reading comprehension, expand their vocabulary, and gain a deeper understanding of grammar structures. Read with translation any EPUB ebook from your device, or choose from our library with 3000+ books and short stories. Reading enhances your creativity, imagination, and empathy. Moreover, reading has been shown to reduce stress, improve mental health, and increase our overall well-being. Dive into a world of dual-language storytelling. Don't just take our word for it - hear what our users have to say: "This app has revolutionized my language study! I use it with my own EPUB files in a language I am studying. The interface is intuitive. It's also very fast to use and provides a smooth experience during long reading sessions." Read in English, German, French, Spanish, Italian, or any other language, build your vocabulary, and improve your grammar skills. With our cross-language ebook reader, translate books on the fly and listen to voiceovers of any sentence or word in your book. Best bilingual reading app available. With duoBooks you will: - Take control of your language learning journey and achieve your goals faster and easier than ever before. - Improve speaking by listening to how words and phrases are pronounced correctly. - Easily incorporate reading into your daily routine and reap the numerous benefits of this powerful skill, all while you learn English (or other languages). - Read English books with translation (or Spanish, French, etc.) easily even if it's not your native language. - Study words with scientifically proven technique (Spaced repetition). Swipe word cards and enjoy the process. Smart Interval system is as effective for memorizing words as English lessons. duoBooks offers short stories specifically created for beginners. They use simple vocabulary, repetitive words, simple dialogues, and uncomplicated sentences. Alternatively, we have a vast selection of classic literature. From the works of Edgar Allan Poe to the novels of Jane Austen. With over 3000+ classic ebooks available and the ability to import your own files, you'll never run out of options to practice your language skills. Whether you're a beginner or an advanced learner, duoBooks is your app for language learning success. Start your journey today with our free language learning app!

Publisher website

Store creative

Screenshots

duoBooks: Language Learning screenshot 1
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duoBooks: Language Learning screenshot 2
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duoBooks: Language Learning screenshot 3
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duoBooks: Language Learning screenshot 4
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duoBooks: Language Learning screenshot 5
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duoBooks: Language Learning screenshot 7
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Competitive set

Similar apps

Deterministic links to real stored apps matched by category, publisher, and comparable performance bands.

Explore the full catalog →

How we estimate

Where every number comes from

App details: Apple iTunes Search API, updated Sep 27, 2026, 9:15 PM.

Rankings: collected chart positions from the listed storefront. Missing ranks are not zeros.

Economics: downloads and gross store consumer spend are estimated, not official Apple or publisher figures.

Model: Lineage not exposed by this aggregate.

Confidence: —; intervals widen when evidence or history is limited.

Last updated: Sep 27, 2026, 9:15 PM.

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See how AppTrendKit separates observations, estimates, coverage, and confidence.

Open methodology
Generated —Public data · no login required