Obkio vs Rocket Calculator
Price, ratings, monetisation and update history for both apps, side by side โ with what reviewers say about each.
Obkio
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Network Performance Intelligence For Everyone. Easy monitoring solution for IT and Network Administrators.
Rocket Calculator
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ApogeeField is an offline flight calculator for low and mid-power model rocketry. Enter your rocket (dry mass, body diameter, drag coefficient, launch-guide length) and pick a motor, and it predicts your apogee, the best ejection delay, max velocity, and rail-exit velocity right at the pad โ with no signal, no account, and no tracking. WHAT IT DOES - Apogee, max velocity and full altitude / velocity / acceleration flight curves โ free. - Recommended ejection delay: ideal coast time mapped to the nearest delay you can actually buy, with the offset in seconds. - Rail-exit velocity with a configurable safety threshold, so you can judge whether the rocket will leave the rail under control. - Compare motors side by side and export your flight card and saved rockets. - Built-in motor database (thrust curves and certified statistics) plus import of your own .eng / .rse files. - Switch freely between metric and imperial units. HOW THE MODEL WORKS (and its limits) ApogeeField runs a deterministic 1-DOF (vertical, point-mass, with launch-angle cosine) flight integration: thrust-curve integration, variable-mass burn (propellant mass is subtracted as impulse is consumed), quadratic drag, and an ISA standard-atmosphere density model, coasting to apogee at the velocity zero-crossing. Every assumption is shown on the results screen so you can line your inputs up against OpenRocket or your own altimeter data. It is an engineering estimate for hobby use โ a starting point, not a guarantee. The model does not account for wind, airframe stability, roll, or weathercocking, so real flights will differ. Always verify with an altimeter. This is not a safety, airworthiness, or legal document, and it does not replace the NAR / Tripoli safety code or local airspace rules โ follow them. PRIVACY & PRICING 100% offline. No account, no network requests, no analytics, no ads. Your rockets and imported motor files stay on your device. One-time unlock โ no subscription. Motor data are numerical facts drawn from publicly submitted thrust-curve files and NAR / Tripoli / CAR certification statistics, stored in our own format with the source and database version shown in the app.
Screenshots
Verdict
The clearest difference is in-app purchases: Obkio at none against Rocket Calculator's 1. Obkio also leads on device support (3 vs 1) and iOS requirement (15.0 vs 17.0). Rocket Calculator's advantage is update cadence (weekly vs every 6 weeks). On price and ads there is nothing between them.
Scored on Price ยท Rating ยท Positive reviews ยท Number of ratings ยท Update frequency ยท Ads ยท In-app purchases ยท Monetization ยท Best chart rank ยท Devices ยท Requires iOS
Both are free to download. Rocket Calculator sells 1 one-off in-app purchase. Obkio asks for nothing beyond the download.
Obkio ships an update every 6 weeks, Rocket Calculator weekly. The most recent releases landed on October 26, 2026 and October 28, 2026 respectively.
| Parameter | Obkio | Rocket Calculator |
|---|---|---|
| Price | Free | Free |
| Update frequency | Every 6 weeks | Weekly โ better |
| Ads | No | No |
| In-app purchases | No โ better | Yes |
| Devices | iPhone, iPad, iPod โ better | iPhone |
| Requires iOS | 15.0 โ better | 17.0 |
| Further details โ not scored | ||
| Size | 61 MB | 1 MB |
| Age rating | 4+ | 4+ |
| Developer | Obkio inc. | ๆฏ ็ |
In-app purchases
Obkio
No in-app purchases
Rocket Calculator
- ApogeeField Unlock$4.99
Questions
Is Obkio free?
Is Rocket Calculator free?
Do Obkio or Rocket Calculator have ads?
Which is updated more often, Obkio or Rocket Calculator?
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