Japanese Grammar
62
Quality Score
Solid
Japanese Grammar
Medium confidence
✍️ bumetric analysis
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Japanese Grammar is an Android app from PORO NIHONGO in the Education category, currently rated 4.3★ across 4,584 ratings. Initial signal reads as largely positive sentiment, users highlighting consistency and feature depth.
Quality Score is 62: Solid (established niche player). For a Education app, that means established niche player. The full BU Investment Matrix below scores 8 dimensions including monetisation, growth, and operational risk.
Track changes month-over-month in the Performance section below: live snapshot history and revenue forecast included.
💰 Monthly revenue · now vs forecast
● Right now
$5.0K
per month
→
12-mo forecast
$5.2K – $10.8K
per month
→
24-mo forecast
$6.4K – $19.2K
per month
MID tier
💡 Grow this revenue
Free AI audit of this app’s store listing
- Title & subtitle keyword fit
- Description hook & conversion structure
- Screenshots, ratings, reviews strategy
Typical impact: +2-5× organic installs
📊 Performance Tracking LIVE
Loading…
Rating
—
Reviews
—
Forecast Revenue / mo
—
Snapshots tracked
0
since first record
ONE-TIME · BUILD
💰 Estimated build cost
$110K
↳ What it cost to build · not monthly revenue
Likely range $80K – $150K
$25K · MVP floor
$100K · indie scale
$500K+ · studio build
📈
Slow ROI — current MRR is well below build cost
Synthetic estimate. Inputs: category complexity, file size, screen count, monetization layer, platform reach, age × team-size proxy. Calibrated against 2024-2026 indie-agency rate surveys. Full math + source list on /methodology.
Where the money goes
| 🧱 MVP baseline (design + 1-store ship) | +$28K |
| 📱 5 unique screens × $4.5K | +$22K |
| 💎 In-app purchase plumbing | +$9K |
| ⚙ Education complexity ×1.20 | +$11K |
| 🌐 Cross-platform reach (iOS + Android) | +$39K |
Total estimate
$110K
ONE-TIME · EXIT VALUE
💵 Estimated acquisition value
$20K
↳ What it would sell for · not monthly revenue
Marketplace range $15K – $25K · 30× MRR multiple
💸
~0.2× build cost (under-water)
Synthetic estimate. Multiple band derived from iap / freemium model + age, rating quality, category demand, and user-base maturity. Calibrated against 2024-2026 indie-app-marketplace closed-deal medians. Full math + comparable deal list on /methodology.
How the multiple was built
| 💎 IAP / freemium model base | 28× MRR |
| 🏷 Education category multiple | +6% |
Final multiple
30× MRR
👥 Estimated audience size
385K
Lifetime downloads (US-equivalent)
Monthly active
69K
Daily active
20K
Synthetic estimate from ratings × category benchmarks. Calibrated against 2024-2026 mobile-attribution retention + DAU/MAU reports. Numbers are US-storefront-equivalent — true global audience can be 5-10× larger for international apps. Full math + source list on /methodology.
How we sized it
| 📲 Education engagement | ~85 installs / rating |
| 🔁 Education D30 retention | 18% |
| 📍 DAU / MAU stickiness | 0.30 |
DAU / MAU
30% sticky
🔬
How we forecast this revenue
MEDIUM CONFIDENCEBaseline
$5.0K/mo · ML-estimated from 234 triggers
Growth rate
+4.0% MoM · MID tier baseline (compound monthly)
6 months
$4.7K – $7.9K
12 months
$5.2K – $10.8K
24 months
$6.4K – $19.2K
Compound growth at +4.0% MoM (tier baseline for MID). Range widens with horizon — typical noise band ±25% at 6mo.. Ranges widen with horizon — distant futures carry more uncertainty.
📊
BU Investment Matrix
Building · 55/100MID TIERcompetitive build-outRevenue Strength
3.7
Product Quality
7.8
Market Position
0.0
Growth Velocity
5.0
Defensibility
9.4
Operational Safety
7.0
Founder Strength
6.3
Monetization Maturity
5.0
- 💰 Revenue: Modest — $3K - $7K/mo · MID tier · medium confidence, trajectory unclear.
- ⭐ Quality: 4.34★ across 4,584 reviews — strong (top 10%).
- 📍 Market: Not yet charting in any of the 9 monitored markets.
- 📈 Growth: ⚠ last update 543d ago — possibly dormant.
- ⚠️ Risk: Moderate — dormant (543d since update).
🎯 For competitors: Strong subscription moat. Hard to outcompete on retention. Better angle: free alternative with one-time purchase, or feature parity for an underserved sub-niche.
💵 For acquirers: Estimated asking range 18-32× monthly = $90K-$160K.
Composite of 8 dimensions computed deterministically from public signals — no LLM, every score traces back to a measurable input. Default weights shown; "compete" / "acquire" / "invest" lenses re-weight without re-fetching.
Range:
💰 Forecast Revenue / mo
MODELRevenue forecast computed from BU's 234 trigger model on each snapshot. Calibrated against ground-truth from 58 verified-revenue apps.
🔬Forecast Breakdown — Why This Estimate?Top 4 of 4 triggers
Our ML model uses 200+ signals from public data. These are the most influential for this app:
| Low install base (4,584 ratings)METRIC | +$1,500 | |
| Good rating (4.3★)METRIC | +$800 | |
| Established app (7y old)METRIC | +$800 | |
| Ad-supported / freemiumMETRIC | +$600 |
METRIC = structural app data · REVIEW = mined from user reviews · ✓ VERIFIED = Stripe-verified anchor (TrustMRR)
📈 Reviews Growth
LIVECumulative review count from first BU snapshot. Each point = a tracked update.
⭐ Rating Trend
LIVEAverage rating evolution. Updates with each new review batch.
Profile & Insights
Everything we know — and don't — about this app and its company.
Identification
- App name
- Japanese Grammar
- Developer
- PORO NIHONGO
- Bundle ID
- com.porolingo.jgrammar
- App Store URL
- Open in App Store
- Category
- Education
- Content rating
- Not found
- Languages
- Not found
Company
- Website
- porostudio.com
- Tagline
- Not found
- Description
- Not found
- Founded
- Not found
- HQ / Address
- Not found
- Employees
- Not found
- Logo
- Not found
Revenue
- Verified revenue / mo
- Not found
- AI revenue estimate / mo
- Not found
- AI annual estimate
- Not found
- ML model estimate / mo
- $709/mo
- Top-grossing rank
- Not found
- All-time revenue
- Not found
- Pricing
- $2.99 - $59.99 per item
Founder
Founder data not yet collected for this app.
Funding
Funding data not yet collected for this app.
Press & Links
Press & Links data not yet collected for this app.
Contacts & Socials
Contacts & Socials data not yet collected for this app.
📈Ratings growth4,584 ratings+44% lifetimeShow 3-year history estimate ▾
Tracked (1 weeks) Pre-tracking estimate (36 weeks) · model-based, ±5% noise · anchored to release date and current value
Profile is built from iTunes Lookup + developer site scrape + ML revenue model. Empty fields show "Not found" — additional sources (Crunchbase, X, IndieHackers, Acquire.com) coming.
📝 About this app
Japanese Grammar is one apps of our ongoing project of PORO designed with purpose of giving helful and easy tool for Japanese learner.
This free Japanese grammar app is offers grammar activities at Beginner, Elementary, Intermediate and Advanced, suitable for learners of all levels, from level JLPT N5 to JLPT N4, JLPT N3, JLPT N2 and JLPT N1.
The application content included 700+ grammar points which are divided into 5 levels, covering almost JLPT level, to help practice and reinforce your Japanese grammar skills.… View full description on the official store →
This free Japanese grammar app is offers grammar activities at Beginner, Elementary, Intermediate and Advanced, suitable for learners of all levels, from level JLPT N5 to JLPT N4, JLPT N3, JLPT N2 and JLPT N1.
The application content included 700+ grammar points which are divided into 5 levels, covering almost JLPT level, to help practice and reinforce your Japanese grammar skills.… View full description on the official store →
App Specs
🔐 Own this app? Claim & verify MRR →🔖 v4.0.2🔄 updated 0d ago📂 Education💰 Free📺 Ad-supported💎 IAP $2.99 - $59.99 per item
🔔
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📝 Description
95
BU Score · Transcendent
Full revenue analysis
Read the article-style breakdown for Japanese Grammar: category rank, percentile, growth signal, comparable apps, and how the forecast is calibrated against verified-MRR anchors in this niche.
More by PORO NIHONGO
View all →📦 Portfolio summaryINDIE studio
8apps·$6K/mocombined
✓ Diversified — top app contributes 18%; risk spread across portfolio
About this analysis
Why medium confidence: 4,584 ratings · no founder-verified revenue (model estimate only).
❓ Frequently Asked Questions
4 answers · auto-generated from this app's public dataHow much does Japanese Grammar make per month?▴
Based on our ML-calibrated revenue forecast, Japanese Grammar earns approximately $708/mo. This is a US-storefront-equivalent estimate; global revenue can be several times larger for internationally-distributed apps. See the methodology page for the full formula and confidence bands.
What apps are like Japanese Grammar?▴
Browse the full Education category catalog to find similar apps with revenue, build cost, audience and tech stack data. Each /p/{slug} page also shows a Compare side-by-side widget with three peer apps from the same niche.
Who makes Japanese Grammar?▴
Japanese Grammar is published by PORO NIHONGO on the Google Play Store. See the full publisher portfolio (other apps by the same developer) via the More by developer block on the product page above.
What is Japanese Grammar's BU Score?▴
Japanese Grammar has a BU Score of 62/100 (Solid). The score combines App Store rating, ratings count, monetization model and revenue signals calibrated against founder-verified MRR anchors. See the BU Score formula.