NumberBook- Spam Blocker
70
Quality Score
Strong
NumberBook- Spam Blocker
by TECH2M
High confidence
✍️ Bumetric analysis
“
NumberBook- Spam Blocker is an Android app from TECH2M in the Communication category, currently rated 3.9★ across 192,591 ratings. Initial signal reads as mostly critical sentiment so far: users flag rough edges and unmet expectations.
Quality Score is 70: Strong (healthy traction). For a Communication app, that means healthy traction. 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
5 snapshots on record
Rating
3.9
Reviews
192,591 reviews
Forecast Revenue / mo
$5.0K
Snapshots tracked
5
since May 2026
ONE-TIME · BUILD
💰 Estimated build cost
$230K
↳ What it cost to build · not monthly revenue
Likely range $170K – $310K
$25K · MVP floor
$100K · indie scale
$500K+ · studio build
📈
Pays back in ~3.8y 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 |
| 💎 In-app purchase plumbing | +$9K |
| ⚙ Communication complexity ×1.65 | +$38K |
| 🌐 Cross-platform reach (iOS + Android) | +$53K |
| ⚙ 12.7y maintenance × ~1-person team | +$76K |
Total estimate
$230K
ONE-TIME · EXIT VALUE
💵 Estimated acquisition value
$175K
↳ What it would sell for · not monthly revenue
Marketplace range $125K – $225K · 34× MRR multiple
💸
~0.8× 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 |
| 📅 12.7y proven track record | +20% |
| ⭐ ★ rating 3.5-4.0 (mixed) | -8% |
| 🏷 Communication category multiple | +5% |
| ⭐ Mature user base (100K+ ratings) | +5% |
Final multiple
34× MRR
👥 Estimated audience size
12.5M
Lifetime downloads (US-equivalent)
Monthly active
1.3M
Daily active
780K
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
| 📲 Communication engagement | ~95 installs / rating |
| 📅 12.7y of rating accumulation | -30% |
| 🔁 Communication D30 retention | 30% |
| 📍 DAU / MAU stickiness | 0.60 |
DAU / MAU
60% sticky
🛠 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 | Communication |
| 📦 Compact Android bundle | → Native Kotlin |
💀 Maintenance status
Likely abandoned
93%
Last shipped 2024-08-31 · 759 days ago
0 · Active
50 · At risk
100 · 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 |
| • 13y old + 1y+ no update | +5% (API deprecation drift) |
Verdict
Likely 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)
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 · 48/100MID TIERunderperforming peersRevenue Strength
3.7
Product Quality
7.8
Market Position
0.0
Growth Velocity
5.0
Defensibility
7.0
Operational Safety
7.0
Founder Strength
3.1
Monetization Maturity
5.0
- 💰 Revenue: Modest — $3K - $7K/mo · MID tier · medium confidence, trajectory unclear.
- ⭐ Quality: 3.88★ across 192,591 reviews — strong (top 10%).
- 📍 Market: Not yet charting in any of the 9 monitored markets.
- 📈 Growth: ⚠ last update 759d ago — possibly dormant.
- ⚠️ Risk: Moderate — dormant (759d since update).
🎯 For competitors: Mixed picture. Worth competing if you have a clear UX or pricing edge — otherwise crowded segment.
💵 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 3 of 3 triggers
Our ML model uses 200+ signals from public data. These are the most influential for this app:
| High install base (192,591 ratings)METRIC | +$12,000 | |
| Mature app (12y old)METRIC | +$1,500 | |
| 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
- NumberBook- Spam Blocker
- Developer
- TECH2M
- Bundle ID
- com.mobiles.numberbookdirectory
- App Store URL
- Open in App Store
- Category
- Communication
- Content rating
- Not found
- Languages
- Not found
Company
- Website
- www.numberbook.net
- Tagline
- Not found
- Description
- Not found
- Founded
- Not found
- HQ / Address
- Not found
- Employees
- Not found
- Logo
- Not found
Revenue
- Reported revenue signal / mo
- Not found
- AI revenue estimate / mo
- Not found
- AI annual estimate
- Not found
- Model estimate / mo
- $5.0K/mo
- Top-grossing rank
- Not found
- All-time revenue
- Not found
- Pricing
- $0.99 - $9.99 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.
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
Don’t stay behind while millions embrace their Numberbook experience!
Stay only in touch with people you love, and don’t waste your time with unwanted communications without abusing your data or invading your privacy.
Numberbook does not pretend to be the only one out there; yet it aims for true quality in its various features.
Numberbook is a trusted, verified and safe community that helps you identify undesired calls or spam calls, granting you a more enjoyable daily mobile experience.
It is a powerful guide that gets you covered and tells you the hot venues that are on your way.… View full description on the official store →
Stay only in touch with people you love, and don’t waste your time with unwanted communications without abusing your data or invading your privacy.
Numberbook does not pretend to be the only one out there; yet it aims for true quality in its various features.
Numberbook is a trusted, verified and safe community that helps you identify undesired calls or spam calls, granting you a more enjoyable daily mobile experience.
It is a powerful guide that gets you covered and tells you the hot venues that are on your way.… View full description on the official store →
App Specs
🔐 Own this app? Claim & verify MRR →🔖 v4.2.2🔄 updated 2y ago📂 Communication💰 Free📺 Ad-supported💎 IAP $0.99 - $9.99 per item🚀 Launched 2014 (12y old)
🔔
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📝 Description
95
BU Score · Transcendent
Full revenue analysis
Read the article-style breakdown for NumberBook- Spam Blocker: category rank, percentile, growth signal, comparable apps, and how the forecast is calibrated against verified-MRR anchors in this niche.
About this analysis
Why high confidence: 192,591 ratings · no founder-verified revenue (model estimate only).
❓ Frequently Asked Questions
10 answers · auto-generated from this app's public dataHow much does NumberBook- Spam Blocker make per month?▴
Based on our ML-calibrated revenue forecast, NumberBook- Spam Blocker earns approximately $5.0K/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 NumberBook- Spam Blocker profitable?▴
With estimated build cost $230K and monthly revenue $5.0K, NumberBook- Spam Blocker looks slow ROI — payback period is around 3.8 years at the current run-rate. Profitability also depends on paid-acquisition spend and refund rate which the public model doesn't see.
How many users does NumberBook- Spam Blocker have?▴
Estimated audience: ~12.5M lifetime downloads, ~1.3M monthly active users, and ~780K daily active users. Derived from ratings count × category installs-per-rating × age decay. US-storefront-equivalent — global audience can be 5-10× larger for internationally-distributed apps.
What apps are like NumberBook- Spam Blocker?▴
Browse the full Communication 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 NumberBook- Spam Blocker built with?▴
Our heuristic places NumberBook- Spam Blocker 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 NumberBook- Spam Blocker still actively maintained?▴
Maintenance status: Likely abandoned (93% 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.
How much would NumberBook- Spam Blocker sell for?▴
Estimated acquisition value: $175K (marketplace range $125K – $225K). Calculated as 34× monthly revenue using the standard multiple for the detected monetization model + adjustments for age, rating quality and category demand. Calibrated against 2024-2026 Flippa / Acquire.com / MicroAcquire closed-deal medians.
When was NumberBook- Spam Blocker last updated?▴
NumberBook- Spam Blocker last shipped a new version on 2024-08-31 — more than 2 year(s) ago. This is the date Apple / Google last accepted a new build, not a content-only push.
Who makes NumberBook- Spam Blocker?▴
NumberBook- Spam Blocker is published by TECH2M 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 NumberBook- Spam Blocker's BU Score?▴
NumberBook- Spam Blocker has a BU Score of 70/100 (Strong). The score combines App Store rating, ratings count, monetization model and revenue signals calibrated against founder-verified MRR anchors. See the BU Score formula.