34
Quality Score
Emerging
Duct Calculator
✍️ bumetric analysis
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Duct Calculator is an Android app from Number Engineer in the Productivity category, currently rated 2.6★ across 38 ratings. Initial signal reads as largely positive sentiment, users highlighting consistency and feature depth.
Quality Score is 34: Emerging (early traction worth watching). For a Productivity app, that means early traction worth watching. 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.
💰 Revenue · today and ahead
Today
$5.0K/mo
In 12 months
$5.2K – $10.8K
In 24 months
$6.4K – $19.2K
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
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Rating
—
Reviews
—
Forecast Revenue / mo
—
Snapshots tracked
0
since first record
ONE-TIME · BUILD💰 Estimated build cost
$150K
↳ What it cost to build · not monthly revenue
Likely range $110K – $200K
$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 |
| ⚙Productivity complexity ×1.10 | +$5K |
| 🌐Cross-platform reach (iOS + Android) | +$35K |
| ⚙7.9y maintenance × ~1-person team | +$47K |
Total estimate$150K
🛠 Estimated tech stack
🤖
Native Android (Kotlin)
High confidence · 80%
Also possible
Flutter
Heuristic guess from app bundle size, category, store description signals, and release-date stack era. Bumetric does not disassemble binaries — for binary-level certainty you would need an SDK intelligence tool or the manifest itself. Reasoning chain on the right. Full ruleset on /methodology.
Signals we read
| 🏷Category context | Productivity |
| 📦Compact Android bundle | → Native Kotlin |
💀 Maintenance status
Likely abandoned
95%
Last shipped 2024-01-18 · 856 days ago
0 · Active50 · At risk100 · Abandoned
Heuristic risk score from time-since-last-update + ratings velocity proxy + Editor's Choice / curated featuring signals. Calibrated against 2024-2025 app-store ranking decay reports. Not a guarantee — a quiet app with a healthy codebase looks the same as an abandoned one until something breaks. Full math on /methodology.
Risk signals
| 📅2y+ since last update | Likely abandoned |
| 👥Small user base (38 ratings) + 7.9y old | +10% (solo-project pattern) |
VerdictLikely abandoned
🔬
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)
Direction
Headwinds: rating drift may slow acquisition
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
Below median · 45/100MID TIERunderperforming peersRevenue Strength
3.7
Product Quality
2.1
Market Position
0.0
Growth Velocity
5.0
Defensibility
9.5
Operational Safety
5.0
Founder Strength
5.9
Monetization Maturity
5.0
- 💰 Revenue: Modest — $3K - $7K/mo · MID tier · medium confidence, trajectory unclear.
- ⭐ Quality: 2.57★ across 38 reviews — weak — significant quality concerns.
- 📍 Market: Not yet charting in any of the 9 monitored markets.
- 📈 Growth: ⚠ last update 856d ago — possibly dormant.
- ⚠️ Risk: Elevated — dormant (856d 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:
| Below-average rating (2.6★)METRIC | −$1,500 | |
| Established app (7y old)METRIC | +$800 | |
| Ad-supported / freemiumMETRIC | +$600 | |
| Pre-traction phase (38 ratings)METRIC | −$300 |
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.
App Specs
🔐 Own this app? Claim & verify MRR →🔖 v2.0🔄 updated 2y ago📂 Productivity💰 Free📺 Ad-supported💎 IAP $1.99 per item🚀 Launched 2018 (7y old)
📝 About this app
Obtain swiftly a diameter or a rectangular size (rounded in increments of 2") to get the right FPM/CFM of an air flow.
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Profile & Insights
Everything we know — and don't — about this app and its company.
Identification
- App name
- Duct Calculator
- Developer
- Number Engineer
- Bundle ID
- com.mathematician.antoine.calculator
- App Store URL
- Open in App Store
- Category
- Productivity
- Content rating
- Not found
- Languages
- Not found
Company
- Website
- numberengineer.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
- $130/mo
- Top-grossing rank
- Not found
- All-time revenue
- Not found
- Pricing
- $1.99 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 growth38 ratings+19% 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.
More by Number Engineer
View all →📦 Portfolio summaryINDIE studio
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✓ Diversified — top app contributes 47%; risk spread across portfolio
Similar apps in Productivity
Full revenue analysis
Read the article-style breakdown for Duct Calculator: category rank, percentile, growth signal, comparable apps, and how the forecast is calibrated against verified-MRR anchors in this niche.
❓ Frequently Asked Questions
8 answers · auto-generated from this app's public dataHow much does Duct Calculator make per month?▾
Based on our ML-calibrated revenue forecast, Duct Calculator earns approximately $130/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.
Is Duct Calculator profitable?▾
With estimated build cost $150K and monthly revenue $130, Duct Calculator looks well below break-even — current monthly revenue is much smaller than the estimated build cost. Profitability also depends on paid-acquisition spend and refund rate which the public model doesn't see.
What apps are like Duct Calculator?▾
Browse the full Productivity 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.
What is Duct Calculator built with?▾
Our heuristic places Duct Calculator on the Native Android (Kotlin) stack (High confidence, 80%). Signals: app bundle size, category context, store-description markers, release-date era. We don't disassemble binaries. Alternative possibilities: Flutter.
Is Duct Calculator still actively maintained?▾
Maintenance status: Likely abandoned (95% abandonment risk). Last shipped version was 2+ years ago. The risk score combines time-since-last-update with Editor's Choice / curated featuring + user-base maturity adjustments.
When was Duct Calculator last updated?▾
Duct Calculator last shipped a new version on 2024-01-18 — more than 2 year(s) ago. This is the date Apple / Google last accepted a new build, not a content-only push.
Who makes Duct Calculator?▾
Duct Calculator is published by Number Engineer 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 Duct Calculator's BU Score?▾
Duct Calculator has a BU Score of 34/100 (Emerging). The score combines App Store rating, ratings count, monetization model and revenue signals calibrated against founder-verified MRR anchors. See the BU Score formula.