Call by Color 36 vs Greatest Common Factor
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Call by Color 36
Quickly call your most important contacts with a single tap. Store up to 36 phone numbers on customizable tiles, organized across three screens. Personalize the look with colors and adjust font sizes for better readability.
- Up to 36 phone numbers
- 12 tiles on three screens
- Customizable font size
- Screen color customization
- Dark mode support
- Tap to call functionality
- No ads
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Store the phone numbers of your friends and family on the speed-dial keys. This app gives you immediate access to your most important phone numbers. No more searching the address book – just tap a tile and start the phone call. Features - 12 tiles on three screens - up to 36 phone numbers - for better legibility the font size can be customized - nice colors - customize the screens with different colors - pick names and numbers from your contacts – supports dark mode - no ads - tap to start a phone call - double tap or long tap a tile to edit Privacy No cloud storage – all data stays on your iPhone. No tracking.
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.
Screenshots
Verdict
The clearest difference is update cadence: Call by Color 36 at every 4 months against Greatest Common Factor's every 38 months. Greatest Common Factor's advantage is device support (3 vs 1) and iOS requirement (14.1 vs 18.5). On price, ads, in-app purchases and monetization model 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
Call by Color 36 costs $0.99 and Greatest Common Factor $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.
Call by Color 36 ships an update every 4 months, Greatest Common Factor every 38 months. Both last shipped on November 3, 2026.
| Parameter | Call by Color 36 | Greatest Common Factor |
|---|---|---|
| Price | $0.99 | $0.99 |
| Rating | — | 5.0 (1 ratings) — better |
| Positive reviews | 0.0% of reviews | — |
| Number of ratings | — | 1 — better |
| Update frequency | Every 4 months — better | Every 38 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Paid |
| Devices | iPhone | iPhone, iPad, iPod — better |
| Requires iOS | 18.5 | 14.1 — better |
| Further details — not scored | ||
| Size | 1 MB | 1 MB |
| Age rating | 4+ | 4+ |
| Developer | Andreas Vogel | H Valeur |
Customer experience
Call by Color 36
Greatest Common Factor
In-app purchases
Call by Color 36
No in-app purchases
Greatest Common Factor
No in-app purchases
Questions
Is Call by Color 36 free?
Is Greatest Common Factor free?
Do Call by Color 36 or Greatest Common Factor have ads?
Which is updated more often, Call by Color 36 or Greatest Common Factor?
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