Greatest Common Factor vs Heliochron
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Greatest Common Factor
This app helps users find the factors of numbers, calculate the Greatest Common Factor (GCF) for two or more numbers, and simplify fractions. It's a useful tool for understanding number theory concepts and performing fraction simplification.
- Find factors of a number
- Calculate GCF of two or more numbers
- Simplify fractions
- Understand number theory concepts
- Fraction simplification tool
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The factors of a number are all the integers that you can evenly divide into that number. The Greatest Common Factor (GCF) is the greatest integer that divides exactly into two or more numbers with no remainder. The Greatest Common Factor is used to simplify fractions. To simplify a fraction, you can divide the numerator and denominator of the fraction by the GCF of the numerator and denominator. Factors, the Greatest Common Factor, and simplifying fractions go hand-in-hand. Use this app to get the factors of a number, get the Greatest Common Factor of two or more numbers, and to simplify fractions.
Heliochron
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Follow the sun. Look at a familiar place differently. Heliochron is a pocket instrument for light, time, and place. Use the AR view to see the calculated sun path over your surroundings, then explore the day and year with two slim, tactile thumbwheels. Notice a courtyard on an architectural walk. Explore a roofline in another season. Look from a possible planter position, or find a reason to return to a favorite view. THE PLACE COMES FIRST On first launch, a short explanation shows why location and camera access are useful. Sun calculations happen on your iPhone, without uploading your location. Allow access to start exploring, or enter coordinates manually in Settings. Narrow azimuth and elevation rulers leave room for the world outside. TIME AT YOUR FINGERTIPS Use Sun to change the time of day and date with separate black-metal wheels. Compare seasonal paths or return to Now with a tap. With obstacle editing off, drag the sun or its path to explore another time; the wheels follow your movement. COMPARE THE YEAR Turn on Year paths in Sun to compare seven representative trajectories, pairing months with similar sun paths. Month labels start in a column on the right and can be dragged along their paths. The overlay starts off and remembers your choice. The paths approximate the 21st of the first named month. MARK WHAT STANDS IN THE WAY Optionally paint trees, buildings, or hills with your finger. Fine diagonal hatching shows your marks, and the sun path dims behind them. Open Obstacles to paint, erase, undo, adjust the brush, or save and restore a named place. KEEP THE VIEW Tap the camera button to save the current sun view, including the camera scene, path, and obstacle marks, to Photos. Photos access is requested only when saving. Saved places and drawings stay locally on your iPhone. No account is required. STAY CURIOUS. KNOW THE LIMITS. Heliochron shows calculated sun positions, not weather or shadows moving across buildings. Obstacle painting is manual, not automatic detection. Marks describe one viewpoint and need checking when you move or return. Alignment depends on location, compass heading, camera tracking, and conditions. Settings includes compass correction and tracking recovery. Avoid pointing the camera directly at the sun for prolonged periods: this may damage the camera. The in-app warning and camera pause are reminders, not physical protection. Pausing capture cannot block sunlight; turn the lens away. For architects and urban planners exploring off duty, garden and balcony growers, and anyone who enjoys looking closer. Not a certified survey, building-compliance, PV-design, or professional solar-assessment tool.
Screenshots
Verdict
The clearest difference is price: Heliochron at Free against Greatest Common Factor's $0.99. Heliochron also leads on update cadence (weekly vs every 38 months). Greatest Common Factor's advantage is device support (3 vs 1) and iOS requirement (14.1 vs 17.0). On ads and in-app purchases 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
Heliochron is free to download; Greatest Common Factor costs $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.
Greatest Common Factor ships an update every 38 months, Heliochron weekly. The most recent releases landed on October 16, 2026 and October 13, 2026 respectively.
| Parameter | Greatest Common Factor | Heliochron |
|---|---|---|
| Price | $0.99 | Free — better |
| Rating | 5.0 (1 ratings) — better | — |
| Number of ratings | 1 — better | — |
| Update frequency | Every 38 months | Weekly — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | — |
| Devices | iPhone, iPad, iPod — better | iPhone |
| Requires iOS | 14.1 — better | 17.0 |
| Further details — not scored | ||
| Size | 1 MB | 28 MB |
| Age rating | 4+ | 4+ |
| Developer | H Valeur | ViSSee AG |
In-app purchases
Greatest Common Factor
No in-app purchases
Heliochron
No in-app purchases
Questions
Is Greatest Common Factor free?
Is Heliochron free?
Do Greatest Common Factor or Heliochron have ads?
Which is updated more often, Greatest Common Factor or Heliochron?
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