Z21
48
Quality Score
Emerging
✍️ GetAppValue analysis
“
Z21 is an Android app from Roco | Fleischmann | Z21 in the Entertainment category, currently rated 3.3★ across 803 ratings. Initial signal reads as mixed reviews: supporters praise core features while critics cite stability and value gaps.
Quality Score is 48: Emerging (early traction worth watching). For a Entertainment 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.
💰 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
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Rating
—
Reviews
—
Forecast Revenue / mo
—
Snapshots tracked
0
since first record
ONE-TIME · BUILD
💰 Estimated build cost
$120K
↳ What it cost to build · not monthly revenue
Likely range $90K – $160K
$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 |
| ⚙ Entertainment complexity ×1.30 | +$17K |
| 🌐 Cross-platform reach (iOS + Android) | +$42K |
Total estimate
$120K
👥 Estimated audience size
120K
Lifetime downloads (US-equivalent)
Monthly active
14K
Daily active
5.6K
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
| 📲 Entertainment engagement | ~150 installs / rating |
| 🔁 Entertainment D30 retention | 12% |
| 📍 DAU / MAU stickiness | 0.40 |
DAU / MAU
40% 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
Below median · 47/100MID TIERunderperforming peersGrowth Velocity
5.0
Founder Strength
3.8
Product Quality
4.6
Revenue Strength
3.7
Monetization Maturity
5.0
Defensibility
8.2
Market Position
0.0
Operational Safety
7.0
- 💰 Revenue: Modest — $3K - $7K/mo · MID tier · medium confidence, trajectory unclear.
- ⭐ Quality: 3.31★ across 803 reviews — below category median.
- 📍 Market: Not yet charting in any of the 9 monitored markets.
- 📈 Growth: last update 183d ago — slow cadence.
- ⚠️ Risk: Moderate — no material risk signals detected.
🎯 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 6 of 6 triggers
Our ML model uses 200+ signals from public data. These are the most influential for this app:
| bugsREVIEW | −$1,800 | |
| Below-average rating (3.3★)METRIC | −$1,500 | |
| Mature app (8y old)METRIC | +$1,500 | |
| slowREVIEW | −$1,200 | |
| Ad-supported / freemiumMETRIC | +$600 | |
| Early-stage install base (803 ratings)METRIC | +$400 |
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
- Z21
- Developer
- Roco | Fleischmann | Z21
- Bundle ID
- eu.z21.app
- App Store URL
- Open in App Store
- Category
- Entertainment
- Content rating
- Not found
- Languages
- Not found
Company
- Website
- www.z21.eu
- 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
- ML model estimate / mo
- $394/mo
- Top-grossing rank
- Not found
- All-time revenue
- Not found
- Pricing
- $17.99 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
Use this app to connect to a Z21 Digital Center. A demo mode is available.
With this app you can manage locomotive libraries, locomotives and locomotive functions, program digital components – and of course control all locomotives with DCC- or Motorola-decoder, as easy and convenient as is only possible with touch-technology.
The digital switchboard Z21 connects your model train unit and your digital locomotives with your iOS device via WLAN. This way you can control the operation on your train layout easily and conveniently from your mobile device.… View full description on the official store →
With this app you can manage locomotive libraries, locomotives and locomotive functions, program digital components – and of course control all locomotives with DCC- or Motorola-decoder, as easy and convenient as is only possible with touch-technology.
The digital switchboard Z21 connects your model train unit and your digital locomotives with your iOS device via WLAN. This way you can control the operation on your train layout easily and conveniently from your mobile device.… View full description on the official store →
App Specs
🔐 Own this app? Claim & verify MRR →🔖 v1.5.3🔄 updated 0d ago📂 Entertainment💰 Free📺 Ad-supported💎 IAP $17.99 per item
🧪
Tech & Domain Intel — z21.eu
- Mail provider
- Microsoft 365
- Tech stack
- Microsoft 365
Derived from public RDAP + DNS TXT records (no scraping, no login).
🔔
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📝 Description
95
BU Score · Transcendent
Full revenue analysis
Read the article-style breakdown for Z21: category rank, percentile, growth signal, comparable apps, and how the forecast is calibrated against verified-MRR anchors in this niche.
More by Roco | Fleischmann | Z21
View all →📦 Portfolio summaryINDIE studio
4apps·$126/mocombined
⚠ Concentrated — top app contributes 91% of combined revenue (single-app dependency)
About this analysis
Why medium confidence: 803 ratings · no founder-verified revenue (model estimate only).
❓ Frequently Asked Questions
4 answers · auto-generated from this app's public dataHow much does Z21 make per month?▴
Based on our ML-calibrated revenue forecast, Z21 earns approximately $394/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 Z21?▴
Browse the full Entertainment 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 Z21?▴
Z21 is published by Roco | Fleischmann | Z21 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 Z21's BU Score?▴
Z21 has a BU Score of 48/100 (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.