Kidoi vs Ruidaichan
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Kidoi
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Unlock Your Child's Curiosity: See It, Hear It, Learn It! Tired of the endless "What's that, Mommy/Daddy?" Now you have the perfect, playful answer! Our AI-powered Object Identifier app turns every curious question into a joyful discovery. Simply point your device's camera at any everyday object, and watch your child's eyes light up as they instantly hear its name and see it identified on screen! Transform Learning into an Engaging Adventure: Smart AI Identification: Our intelligent app uses advanced AI to quickly and accurately recognize a vast world of objects around you – from fruits in the kitchen to animals in a book! Hear, See & Learn: Clear, friendly voices announce the object's name, helping with pronunciation and vocabulary building. See the name spelled out to encourage early literacy skills. You Are in Control: Easily customize the learning experience! Hide specific objects from detection or even edit their descriptions to keep lessons focused, personalized, and age-appropriate. You decide what's part of your child's discovery journey. Explore in 10+ Languages: Perfect for bilingual families or for gently introducing your child to new words in different languages. A fun and effortless way to broaden their horizons! Choose Your Friendly Guide: Make learning even more special by selecting from a variety of premium, child-friendly voices that your little one will love! Why Parents & Kids Love Our App: This app is more than just an object identifier; it's a tool to foster a love for learning. Designed for toddlers, preschoolers, and early learners, it helps build vocabulary, enhances observational skills, and makes education an interactive experience. We've created a safe, intuitive, and engaging environment for your child to explore. Plus, enjoy a completely ad-free experience focused purely on learning and fun! Core features work offline, making it perfect for learning anytime, anywhere! Key Features at a Glance: Instant, AI-powered object recognition Clear and friendly voice narration Object names displayed for reading practice Learn object names in over 10 different languages Parental controls: Hide objects & edit descriptions Variety of premium voice guides Safe & Ad-Free: Purely focused on learning Works Offline: Learn on the go! Child-friendly interface: Easy to use and full of wonder! Download today and watch your child see, hear, and learn about the world around them like never before! Let the joyful discoveries begin! Terms of Use: https://www.mbefe.com/#/koi/terms-conditions Privacy Policy: https://www.mbefe.com/#/koi/privacy-policy
Ruidaichan
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Create printable math worksheets from elementary school word problems. This app automatically generates similar practice worksheets (A4 size) from a photo of a math problem. Designed for elementary school students, especially grades 1–3, to practice word problems and basic calculations at home. Great for extra practice when children need more repetition with the same type of problems. 【Good for situations like】 * Homework is not enough practice * You want more problems of the same type * Review elementary school word problems * Print worksheets at home * Create extra worksheets for cram schools or tutoring * Add review problems for classrooms or after-school programs * Give similar but different worksheets to each student 【Features】 * Scan math problems using OCR (photo text recognition) * Automatically generate similar practice questions * Create printable A4 PDF worksheets * Save, share, and print generated worksheets 【How to use】 1. Take a photo of a math problem 2. Generate a similar worksheet 3. Print or share the PDF worksheet Free monthly usage is available. Images and OCR text are only sent for worksheet generation and are not stored. Q. Can 4th graders use this app? A. Yes. While mainly designed for grades 1–3, it can also be used for 4th grade review and extra practice. Q. Can it generate only word problems? A. Yes. The app supports generating similar word problems. Q. Can I print the worksheets? A. Yes. Generated worksheets can be printed on A4 paper using home printers or convenience store printing services. Q. Can I save worksheets as PDF files? A. Yes. Worksheets can be saved and shared as PDF files. Q. Can it generate more problems of the same type? A. Yes. The app creates similar practice problems based on the original question. Q. Is it useful for homeschooling or home learning? A. Yes. It is designed for home learning, review practice, and extra exercises. Q. Does the app use OCR? A. Yes. The app reads math problems from photos using OCR technology. Q. Does it support calculation problems too? A. Yes. Both word problems and basic calculation problems are supported. Q. What type of learning app is this? A. This is a printable worksheet generation and review-focused math learning app that uses OCR to read problems and generate similar worksheets. Q. What situations is this app used for? A. It is used for home learning, cram school review worksheets, classroom review practice, homework support, and repeated practice of weak areas. Q. Can teachers use this app? A. Yes. Teachers, tutors, and cram schools can use it to quickly create additional practice worksheets. Terms of Use: https://github.com/MakikoOhashi/kima-app-policies/blob/main/ruidaichan-terms.md Privacy Policy: https://github.com/MakikoOhashi/kima-app-policies/blob/main/ruidaichan-privacy.md
Screenshots
Verdict
The clearest difference is update cadence: Ruidaichan at every 5 days against Kidoi's fortnightly. 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
Both are free to download. Kidoi sells 2 in-app purchases, starting at $0.99 per month and Ruidaichan sells 2 in-app purchases, starting at $1.99 per month. Whichever you choose, the download price is not the number that matters.
Kidoi ships an update fortnightly, Ruidaichan every 5 days. The most recent releases landed on October 24, 2026 and October 19, 2026 respectively.
| Parameter | Kidoi | Ruidaichan |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (2 ratings) — better | — |
| Number of ratings | 2 — better | — |
| Update frequency | Fortnightly | Every 5 days — better |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Devices | iPhone, iPad — better | iPhone |
| Requires iOS | 17.6 | 16.6 — better |
| Further details — not scored | ||
| Size | 155 MB | 18 MB |
| Age rating | 4+ | 4+ |
| Developer | MUSTAFA BATIN EFE | Naoki Ohashi |
In-app purchases
Kidoi
- Premium Monthly$0.991 Month
- Premium Yearly7 Days trial$9.991 Year
Ruidaichan
- Light Plan$1.991 Month
- Premium Plan$4.991 Month









