57
BU Score
Solid
Stark Bag
✍️ BU Analytics Review
“
Stark Bag is an iOS app from Postra AB in the Health & Fitness category, currently rated 4.8★ across 50 ratings. Initial signal reads as mixed reviews — supporters praise core features while critics cite stability/value gaps.
Our BU Score puts it at 57 — Solid (established niche player). For a Health & Fitness app, that means established niche player.
Track changes month-over-month in the Performance section below — live snapshot history and revenue forecast included.
creator
📊 Performance Tracking LIVE
Loading…
Rating
—
Reviews
—
Forecast Revenue / mo
—
Snapshots tracked
0
since first record
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 5 of 5 triggers
Our ML model uses 200+ signals from public data. These are the most influential for this app:
| Paid app ($0.00)METRIC | +$2,800 | |
| Excellent rating (4.8★)METRIC | +$2,200 | |
| Mature app (11y old)METRIC | +$1,500 | |
| Localized (7 languages)METRIC | +$600 | |
| Pre-traction phase (50 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.
🗓️ Snapshot Timeline
HISTORYEach bar shows a tracked update and the metric delta from the previous snapshot.
App Specs
🔐 Own this app? Claim & verify MRR →💾 18 MB🔞 4+📱 iOS 12.0+🔖 v2.5.13🔄 updated 4y ago🌐 EN, FR, DE, IT, PT +2📂 Health & Fitness💰 Paid🚀 Launched 2014 (11y old)
📝 About this app
Optimize your results with Virtual Trainer Bag!
- Be inspired by 27 exercises presented in sharp HD video.
- Create your own personal workout.
- Get a full body workout with exercises in all ranges of difficulty
- While working out, follow the step by step workout-feature which take you through the workout using timers and your chosen specifics.
- The timers support different workout types including Tabata, HIIT and Circuit training.
- Challenge yourself, get rewards and keep track of your score.
- Find exercises targeting specific muscle groups.
Integration with Apple Health: Save burned calories and performed workouts.
The Bag, is a crescent-shaped exercise equipment used in strength training, plyometric weight training, cardiovascular training, and general physical fitness.
Exercises are performed by the professional instructor, Martin Söderblom.
- Be inspired by 27 exercises presented in sharp HD video.
- Create your own personal workout.
- Get a full body workout with exercises in all ranges of difficulty
- While working out, follow the step by step workout-feature which take you through the workout using timers and your chosen specifics.
- The timers support different workout types including Tabata, HIIT and Circuit training.
- Challenge yourself, get rewards and keep track of your score.
- Find exercises targeting specific muscle groups.
Integration with Apple Health: Save burned calories and performed workouts.
The Bag, is a crescent-shaped exercise equipment used in strength training, plyometric weight training, cardiovascular training, and general physical fitness.
Exercises are performed by the professional instructor, Martin Söderblom.
🆕 What's New · v2.5.13
* New name
* Bugfixes
* Bugfixes
Profile & Insights
Everything we know — and don't — about this app and its company.
Identification
- App name
- Stark Bag
- Developer
- Postra AB
- Bundle ID
- se.virtualtrainer.VT-BULGARIANBAG
- App Store URL
- Open in App Store
- Category
- Health & Fitness
- Content rating
- 4+
- Languages
- EN, FR, DE, IT, PT, ES, SV
Company
- Website
- Not found
- Tagline
- Today
- Description
- Find apps and games for iPhone, iPad, Mac, and more on the App Store.
- Founded
- Not found
- HQ / Address
- Not found
- Employees
- Not found
- Logo
- OG image
Revenue
- Verified revenue / mo
- Not found
- AI revenue estimate / mo
- Not found
- AI annual estimate
- Not found
- ML model estimate / mo
- $86/mo
- Top-grossing rank
- Outside top 100 in US Health & Fitness
- All-time revenue
- Not found
- Pricing
- Not found
Founder
- Name
- Not found
- X / Twitter
- Not found
- Not found
- GitHub
- Not found
- X followers
- Not found
- Public statements
- Not found
Funding
- Total raised
- Not found
- Last round
- Not found
- Investors
- Not found
- Crunchbase
- Not found
- AngelList
- Not found
Press & Links
- Articles found
- Not found
- Listed on
- Not found
- Blog
- https://apps.apple.com/us/app/letterloop-group-newsletters/id6468623700
- Press / News
- Not found
Contacts & Socials
- Socials
- Not found
- Not found
- Phone
- Not found
- Contact page
- Not found
- About page
- https://apps.apple.com/us/iphone/story/id1603519753
📈Ratings growth50 ratings+4900% lifetimeShow 3-year history estimate ▾
Tracked (5 weeks) Pre-tracking estimate (37 weeks) · model-based, ±5% noise · anchored to release date and current value
🌍Geographic ReachNot ranked
This app is currently outside the top 100 grossing in all 9 countries we monitor (US, UK, DE, FR, JP, CA, AU, BR, IN). Niche or new apps often launch this way — popularity rankings appear once daily revenue clears the regional threshold.
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 Postra AB
View all →
More Health & Fitness
WeightWatchers Program
★ 4.8 · 2,340,314 reviews
MyFitnessPal: Kalorien Tracker
★ 4.7 · 2,329,701 reviews
Calm: Meditation und Schlaf
★ 4.8 · 1,952,102 reviews
Flo Perioden- & Zyklus-Tracker
★ 4.8 · 1,862,244 reviews
Motivation - Tägliche Zitate
★ 4.8 · 1,048,916 reviews
AllTrails: Hike, Run & Walk
★ 4.9 · 1,026,602 reviews
Kaiser Permanente
★ 4.8 · 997,620 reviews
Headspace: Meditation & Schlaf
★ 4.8 · 974,051 reviews
Browse BU Analytics
📚 All 55,000+ Books
🜍 Alchemy & Hermeticism
🔮 Magic & Ritual
🌙 Witchcraft & Paganism
⭐ Astrology & Cosmology
🃏 Divination & Tarot
📜 Health & Fitness
✡️ Kabbalah & Jewish Mysticism
🕉️ Mysticism & Contemplation
🕊️ Theosophy & Anthroposophy
🏛️ Freemasonry & Secret Societies
👻 Spiritualism & Afterlife
📖 Sacred Texts & Gnosticism
👁️ Supernatural & Occult Fiction
🧘 Spiritual Development
📚 Esoteric History & Biography
Info
About BU Analytics