Comparison

CalcFast vs World Clock Pro

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

CalcFast

A fast and elegant calculator for Apple devices that displays your calculation history. It offers a Today Extension for quick access and supports Apple Watch, external keyboards, and VoiceOver.

Highlights
  • Calculation history display
  • Today Extension for quick calculations
  • Apple Watch app
  • Dark/light mode selection
  • External keyboard support
  • VoiceOver support
Features
Read full description

Fast and simple calculator for iPad, iPhone and Apple Watch that shows the calculation history, includes a Today Extension that allows for fast calculation by swiping down and 3D Touch for quick interactions. Numbers are formatted for your country, i.e. period in the US and comma in Europe. Ever lost your train of thought half way through a calculation and thought how handy it would be to review your calculations. The aim of this Calculator is to be fast, elegant and simple. Features: - The calculator can open side by side or over other apps in iPadOS. - Select dark or light mode. - External keyboard support. - Smart Apple Watch Calculator included. - Light weight Today Extension included. - Calculations shown when input and on tape. - Key click confirms pressing of buttons, which may be turned off. - Previous calculation is repeated when the equal sign is pressed. - Numbers are shown in local format, depending on your Region Formats, i.e. comma used in Europe. The number of decimal digits may be set in the Settings. - VoiceOver is supported. - Calculations Tape may be deleted by Tapping on it.

About

World Clock Pro

Easily track and convert time across multiple global time zones. Schedule events, share accurate times instantly, and access a vast database of cities and time zones. Ideal for international communication and planning.

Highlights
  • Universal clock access
  • Effortless time conversion
  • Schedule calendar events
  • Instant time sharing
  • Large city and timezone database
  • Automatic timezone updates
Features
Read full description

TIMEZONE CALCULATOR – YOUR ULTIMATE WORLD TIME COMPANION Master global time with a tool that is clear, concise, and built for busy international lives. Whether you’re scheduling business meetings or connecting with friends overseas, World Clock Pro keeps you in sync—simply and directly. ESSENTIAL FEATURES UNIVERSAL CLOCK ACCESS: View accurate times in cities around the world—New York, London, Tokyo, Sydney. No fuss, just the facts. EFFORTLESS TIME CONVERSION: Swipe to convert and compare time zones with precision. Plan your calls and meetings with ease. SCHEDULE WITH CONFIDENCE: Create and integrate calendar events quickly. Organize trips, group activities, and international calls without confusion. INSTANT TIME SHARING: Share exact times via email, SMS, social media, or messengers. Coordination is just a click away. HUGE CITY & TIMEZONE DATABASE: Access over 160,000 cities and popular time zones like GMT, UTC, EST, and PST at your fingertips. WHY THIS APP MATTERS Say goodbye to timezone confusion. This isn’t just another world clock—it’s a powerful tool for global thinkers, frequent travelers, and anyone who values clear, reliable time data. Streamline your schedule and manage your day without delay. EXTEND YOUR EXPERIENCE For a deeper dive into global time management, World Clock Pro is also available on Mac. Just search “World Clock Pro” in the Mac AppStore * * * World Clock Pro offers a premium subscription: Subscribe to get access to unlimited timezones, and timely automatic updates of our timezone database of more than 160,000 locations and timezones. – Length of subscription: 1 month or 1 year – Payment will be charged to iTunes Account at confirmation of purchase – Subscription automatically renews unless auto-renew is turned off at least 24-hours before the end of the current period – Account will be charged for renewal within 24-hours prior to the end of the current period, and identify the cost of the renewal – Subscriptions may be managed by the user and auto-renewal may be turned off by going to the user's Account Settings after purchase – Any unused portion of a free trial period, if offered, will be forfeited when the user purchases a subscription to that publication, where applicable – Terms & Conditions: https://timemaster.s3.amazonaws.com/Time-master-terms.pdf – Privacy Policy: https://timemaster.s3.amazonaws.com/Time-master-privacy-policy.pdf

Screenshots

CalcFast3 screens
World Clock Pro4 screens

Verdict

The call

The clearest difference is rating: World Clock Pro at 4.8 against CalcFast's 4.2. World Clock Pro also leads on ratings volume (1.3K vs 20) and iOS requirement (13.0 vs 18.0). CalcFast's advantage is in-app purchases (none vs 6). On price, review sentiment, update cadence and ads 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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. World Clock Pro sells 5 in-app purchases, starting at $1.99 per month. CalcFast asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

World Clock Pro holds the better App Store score, 4.8 against 4.2. That said, the two scores are not equally well evidenced: World Clock Pro has 1.3K ratings behind it against 20, so its average is the more settled of the two. Written reviews complicate that: 78% of CalcFast's written reviews are positive against 77% of World Clock Pro's, so the app with the better star average is not the one people write more warmly about.

UpkeepUpdate frequency

Both ship on a similar rhythm, roughly every 2 months. The most recent releases landed on September 19, 2026 and September 3, 2026 respectively.

Scorecard5 real differences · 5 level
CalcFast versus World Clock Pro: the parameters behind the verdict, then further details
ParameterCalcFastWorld Clock Pro
PriceFreeFree
Rating4.2 (20 ratings)4.8 (1.3K ratings) — better
Positive reviews78.3% of reviews — better76.7% of reviews
Number of ratings201.3K — better
Update frequencyEvery 2 monthsEvery 2 months
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFree — betterSubscription
DevicesiPhone, iPadiPhone, iPod
Requires iOS18.013.0 — better
Further details — not scored
Size6 MB41 MB
Age rating4+4+
DeveloperHannes SverrissonAlex Komarov Inc.

Customer experience

CalcFast

All ratings20 ratings
Positive80.0%
Neutral0.0%
Negative20.0%
Written reviews23 reviews
Positive78.3%
Neutral4.3%
Negative17.4%

World Clock Pro

All ratings1,349 ratings
Positive95.3%
Neutral1.9%
Negative2.8%
Written reviews206 reviews
Positive76.7%
Neutral4.9%
Negative18.4%

Bugs and requests

CalcFast

Not enough reviews yet to summarise bugs or requests.

World Clock Pro

Reported bugs

3 issues
  • Widget not working on iOS 14 and newer
  • Issues with local time zone detection and display
  • Inconsistent behavior after app updates

Requested features

4 requests
  • Add date function for future time zone changes
  • Ability to customize and sort displayed time zones
  • Implement an Apple Watch app
  • Improve widget functionality and customization

In-app purchases

None

CalcFast

No in-app purchases

5 purchases

World Clock Pro

Subscriptions5
  • 1 month$1.991 Month
  • 1 month2 variants$2.991 Month
  • 1 year3 Days trial$9.991 Year
Show 2 more
  • 1 year3 Days trial$11.991 Year
  • 1 year3 Days trial$19.991 Year

Questions

Is CalcFast free?
CalcFast is free to download, with no in-app purchases.
Is World Clock Pro free?
World Clock Pro is free to download, with in-app purchases available.
Which has better reviews, CalcFast or World Clock Pro?
World Clock Pro is rated higher. CalcFast averages 4.2 out of 5 from 20 ratings, while World Clock Pro averages 4.8 from 1.3K ratings.
Do CalcFast or World Clock Pro have ads?
Neither CalcFast nor World Clock Pro shows ads.
Which is updated more often, CalcFast or World Clock Pro?
CalcFast ships an update every 2 months, and World Clock Pro every 2 months. Most recently, CalcFast was updated on September 19, 2026 and World Clock Pro on September 3, 2026.

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