FX991 EX Original Calculator
61
Quality Score
Solid
✍️ bumetric analysis
“
FX991 EX Original Calculator is an Android app from MARTINs in the Tools category, currently rated 3.4★ across 34,457 ratings. Initial signal reads as mixed reviews: supporters praise core features while critics cite stability and value gaps.
Quality Score is 61: Solid (established niche player). For a Tools 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
$70K
↳ What it cost to build · not monthly revenue
Likely range $50K – $95K
$25K · MVP floor
$100K · indie scale
$500K+ · studio build
📈
Pays back in ~5.0y at current MRR
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 |
| ⚙ Tools complexity ×0.90 | $-5049 |
| 🌐 Cross-platform reach (iOS + Android) | +$24K |
Total estimate
$70K
ONE-TIME · EXIT VALUE
💵 Estimated acquisition value
$15K
↳ What it would sell for · not monthly revenue
Marketplace range $10K – $15K · 11× MRR multiple
💸
~0.2× build cost (under-water)
Synthetic estimate. Multiple band derived from ad-supported + 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
| 📺 Ad-supported base | 15× MRR |
| ⭐ ★ rating < 3.5 (weak) | -18% |
| 🏷 Tools category multiple | -8% |
Final multiple
11× MRR
👥 Estimated audience size
6.5M
Lifetime downloads (US-equivalent)
Monthly active
1.4M
Daily active
250K
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
| 📲 Tools engagement | ~190 installs / rating |
| 🔁 Tools D30 retention | 22% |
| 📍 DAU / MAU stickiness | 0.18 |
DAU / MAU
18% 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
Stalled · 39/100MID TIERno growth momentumRevenue Strength
3.7
Product Quality
6.7
Market Position
0.0
Growth Velocity
5.0
Defensibility
5.2
Operational Safety
5.0
Founder Strength
4.4
Monetization Maturity
1.0
- 💰 Revenue: Modest — $3K - $7K/mo · MID tier · medium confidence, trajectory unclear.
- ⭐ Quality: 3.35★ across 34,457 reviews — solid.
- 📍 Market: Not yet charting in any of the 9 monitored markets.
- 📈 Growth: ⚠ last update 2512d ago — possibly dormant.
- ⚠️ Risk: Elevated — dormant (2512d since update).
🎯 For competitors: Vulnerable. Quality drift + slow updates create a clear opening for a fresh competitor with active dev cadence.
💵 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:
| Mid install base (34,457 ratings)METRIC | +$5,500 | |
| Below-average rating (3.4★)METRIC | −$1,500 | |
| Established app (6y 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
- FX991 EX Original Calculator
- Developer
- MARTINs
- Bundle ID
- com.fx991ex.fx991exoriginal
- App Store URL
- Open in App Store
- Category
- Tools
- Content rating
- Not found
- Languages
- Not found
Company
- Website
- martinslab.de
- 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
- $115/mo
- Top-grossing rank
- Not found
- All-time revenue
- Not found
- Pricing
- Not found
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 growth34,457 ratings+42% 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
This calculator application is meant to be a 1:1 clone of the CASIO FX-991 EX/DEX, the most intuitive and at the same time most powerful calculator on the market. It is also very common and convenient.
If you want to have this calculator as an app, please let us know. Mail us and rate this app positively! If there is enough demand, we will develop it. First steps of development are already done.
This is a market research and development request application.
Please visit https://martinslab.de/privacy-policy-terms-and-conditions/ to see our privacy policy on collected data.
If you want to have this calculator as an app, please let us know. Mail us and rate this app positively! If there is enough demand, we will develop it. First steps of development are already done.
This is a market research and development request application.
Please visit https://martinslab.de/privacy-policy-terms-and-conditions/ to see our privacy policy on collected data.
App Specs
🔐 Own this app? Claim & verify MRR →🔖 v1.1🔄 updated 0d ago📂 Tools💰 Free📺 Ad-supported
🔔
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📝 Description
95
BU Score · Transcendent
Full revenue analysis
Read the article-style breakdown for FX991 EX Original Calculator: category rank, percentile, growth signal, comparable apps, and how the forecast is calibrated against verified-MRR anchors in this niche.
More by MARTINs
View all →📦 Portfolio summaryINDIE studio
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✓ Diversified — top app contributes 38%; risk spread across portfolio
About this analysis
Why high confidence: 34,457 ratings · no founder-verified revenue (model estimate only).
❓ Frequently Asked Questions
4 answers · auto-generated from this app's public dataHow much does FX991 EX Original Calculator make per month?▴
Based on our ML-calibrated revenue forecast, FX991 EX Original Calculator earns approximately $1.2K/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 FX991 EX Original Calculator?▴
Browse the full Tools 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 FX991 EX Original Calculator?▴
FX991 EX Original Calculator is published by MARTINs 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 FX991 EX Original Calculator's BU Score?▴
FX991 EX Original Calculator has a BU Score of 61/100 (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.