Formula & Units vs AR Orbits
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Formula & Units
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Formula & Units is an ultimate tool for calculation of complex scientific expressions and convertion of scientific units. Expressions may be comprised of variables and constants, possessing numeric values and sets of units. Support and info at www.volard.wordpress.com The application interface consists of three custom (A, B, C) value-units expressions and six preset constants, which may be added to the final expression field by pressing the corresponding buttons. Value-Units Expression contains three fields: value field, numerator (top) units field and denominator (bottom) units field. Units must be typed exactly as they appear in the provided list in the Help section. Power of unit is typed directly after unit : s2. Metric prefixes or unit prefixes are recognized automatically: mm = 1.0e-3 m, kA = 1000 A. Metric prefix micro- (1e-6), is changed to 'u'. Additional Units can be added upon request through www.volard.wordpress.com. Example of unit expression as it should appear in numerator or denominator fields: mm2*s*kg*uA-2*MPa-2. Upon addition or subtraction, unit expressions should be of the same dimensionality! Meters cannot be added to Pascals!!! Application provides set of widely used physico-chemical constants. Pressing the corresponding constant button adds the value to the final field. Presets are: Na - Avogadro's constant, h - Planck constant, F - Faraday constant, R - gas constant, kB - Boltzmann constant, g - acceleration of gravity, e - elementary charge, Pi - pi constant. (All in SI units) The final expression is a regular scientific formula consisting of value-units expressions, regular math operations, numbers and functions. Available math functions are provided with buttons-shortcuts. Dot is used as a decimal point. Pressing "Calculate" button evaluates final expression. By default, application converts all units to International System of Units (SI), but it is possible to set the required units directly to the final (where result is shown) units fields before calculation, then the result will be adjusted to meet the requirement. The resulting final expression can be copied to A expression field, by pressing a "A^" top bar button, for further conversion or calculations. For a simple conversion, type the expression that should be converted to A field and preferred units to the B field. Special attention should be paid to dimensionality! For example: To change m3 to US Gallon in expression s*kg/m3, type gal-1 to numerator field or gal to denominator field in the B expression. Press 'convert' button to get the final converted result. For conversion numeric value of B expression has no meaning. Examples can be found at www.volard.wordpress.com.
AR Orbits
Explore the solar system and understand satellite mechanics through augmented reality. This app simplifies complex astrophysics concepts, allowing users to create and plot their own orbits, making rocket science accessible for learning and homework.
- Augmented reality exploration
- Satellite mechanics simulation
- Orbit plotting and creation
- Astrophysics homework assistance
- Solar system discovery
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Have you ever wondered how satellites work? The phone or tablet you’re holding right now is connected to the internet via satellites, which help you navigate your car, track the weather, and discover new and exciting things about the solar system we live in. With AR Orbits, anyone can become a rocket scientist with the tap of a button. Learn how to plot and create your own orbits, or use the app to help you with your astrophysics homework. Explore a world of physics with AR Orbits.
Screenshots
Verdict
The clearest difference is price: AR Orbits at Free against Formula & Units's $3.99. AR Orbits also leads on iOS requirement (13.0 vs 16.0). Formula & Units's advantage is update cadence (every 2 months vs every 18 months). On ads, in-app purchases and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
AR Orbits is free to download; Formula & Units costs $3.99 up front. Neither carries in-app purchases, so what you see is what you pay.
Formula & Units ships an update every 2 months, AR Orbits every 18 months. The most recent releases landed on August 20, 2026 and June 1, 2026 respectively.
| Parameter | Formula & Units | AR Orbits |
|---|---|---|
| Price | $3.99 | Free — better |
| Rating | — | 4.9 (11 ratings) — better |
| Positive reviews | — | 100.0% of reviews |
| Number of ratings | — | 11 — better |
| Update frequency | Every 2 months — better | Every 18 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | — | Free |
| Devices | iPhone, iPad | iPhone, iPad, iPod — better |
| Requires iOS | 16.0 | 13.0 — better |
| Further details — not scored | ||
| Size | 1 MB | 58 MB |
| Age rating | 4+ | 4+ |
| Developer | Roman Volinsky | Turner Thornberry |
In-app purchases
Formula & Units
No in-app purchases
AR Orbits
No in-app purchases







