Comparison

JSCalculator vs Time Left

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

Head to head
About

JSCalculator

This advanced calculator evaluates expressions as you type, eliminating the need for an equals key. It supports complex formulas, variables, and predefined constants, making it ideal for scientific and engineering tasks.

Highlights
  • Instant evaluation as you type
  • Formula entry with variables
  • Multi-step formulas
  • History of entered formulas
  • Predefined constants of nature
  • Copy and paste functionality
Features
Read full description

Not an imitation of a limited stand alone electronic calculator of old. This is a calculator that exploits the power of the device it is running on. It works slightly differently, but it allows for more flexibility. As an example, JSCalculator evaluates what you type without the need of hitting "=" or an enter key. In this calculator, the "=" key is for assigning values to variables, not for telling it to execute a calculation! In JSCalculator, what you enter can be a standard calculation like "1+2", but it can also be much more! JSCalculator was developed by a physicist who needed to be able to enter a short formula on an iOS device, and have it evaluated for various values of some parameters. In addition to predefined functions and the ability to edit even longer or multi-step expressions, this calculator provides a set of the most used constants of nature (in SI units). Short list of the main features: - No enter key. No equal sign that must be pressed to execute a calculation. - What you write is evaluated as you type, and you immediately see the result. - Enter formulas, not just calculations. - Use multi-step formulas with intermediate (algebraic) variables. - Example of a multi-step formula: "p = sqr(a)+b;sin(p)/p" - Every formula you enter is stored, so that you can re-use it the next time you use the calculator. Cycle through all formulas with arrow buttons on the front screen or via standard lists. - Intelligent exponential/engineering notation for the calculated results (optional). - Several predefined mathematical functions. - Predefined constants of nature. - Ability to copy and paste. Ability to copy the result of calculations, or the values of one of the predefined constants of nature. - Numeric keys for typing numbers, predefined functions, or constants, but the standard keyboard will appear when the "T" button is pressed. Any issues or questions? Use our feedback form to tell us about them: http://ivpadev.com/support.html

About

Time Left

This app helps you visualize the finite nature of your time, displaying the remaining days, months, and years. It encourages a more present and creative life by emphasizing the preciousness of each moment. Your data remains private, with no notifications or ads.

Highlights
  • Displays remaining days, months, and years
  • Emphasizes the preciousness of time
  • Encourages a happy and creative life
  • No notifications, ads, or sign-up
  • Private data storage
  • Unlockable widgets and customization (Pro)
Features
Read full description

No notifications. No ads. No sign-up. Just you and your time. TIME LEFT DESCRIPTION Sometimes life seems really short, and other times impossibly long. This app will help you to emphasize that it’s most certainly finite. Time Left shows you, the days, months, and years you have left and that they are all you have got. Don’t be afraid, that means the only appropriate word to describe your time left is “precious”. So I hope this app will enable you to create a life in which you will be happy and creative. WHAT ABOUT YOUR PRIVACY? I think Privacy is a fundamental human right. To that end, I have designed Time Left from the ground up without any external framework. In this way, your data, like your birthdate, stays entirely private. HOW CAN YOU HELP ME? As I don’t collect any data on this app, to improve it I need your help! You can send me an email to julien@lacroix.dev for any feedback, issues, or bugs on this app or just to say “Hello!”. I answer every email! ********** A special thank you to Wait But Why for this amazing article (https://waitbutwhy.com/2014/05/life-weeks.html). Without their work, this app would not have seen the light of day. ********** TIME LEFT PRO - Unlock widgets & skins. - Unlimited moments. - Live Photos in Life Calendar. - Automatically access all future features and widgets. - Support an indie developer. ********** Terms of Use: https://gettimeleft.app/terms Privacy Policy: https://gettimeleft.app/privacy

Screenshots

JSCalculator3 screens
Time Left4 screens

Verdict

The call

The clearest difference is price: Time Left at Free against JSCalculator's $0.99. Time Left also leads on update cadence (every 6 days vs every 25 months) and ratings volume (237 vs 2). JSCalculator's advantage is in-app purchases (none vs 5) and rating (5.0 vs 4.6). On 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

Time Left is free to download; JSCalculator costs $0.99 up front. Time Left sells 5 in-app purchases, starting at $4.99 per 7 days. JSCalculator asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

JSCalculator holds the better App Store score, 5.0 against 4.6. That said, the two scores are not equally well evidenced: Time Left has 237 ratings behind it against 2, so its average is the more settled of the two. Written reviews point the same way: 100% of JSCalculator's written reviews are positive against 73% of Time Left's.

UpkeepUpdate frequency

JSCalculator ships an update every 25 months, Time Left every 6 days. The most recent releases landed on October 3, 2026 and October 20, 2026 respectively.

Scorecard9 real differences · 1 level
JSCalculator versus Time Left: the parameters behind the verdict, then further details
ParameterJSCalculatorTime Left
Price$0.99Free — better
Rating5.0 (2 ratings) — better4.6 (237 ratings)
Positive reviews100.0% of reviews — better73.5% of reviews
Number of ratings2237 — better
Update frequencyEvery 25 monthsEvery 6 days — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationPaidFree with in-app purchases — better
DevicesiPhone, iPad, iPod — betteriPhone
Requires iOS15 — better17.0
Further details — not scored
Size1 MB42 MB
Age rating4+4+
DeveloperIvan BiaggioJulien Lacroix

Customer experience

JSCalculator

All ratings2 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews2 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

Time Left

All ratings237 ratings
Positive89.0%
Neutral2.5%
Negative8.4%
Written reviews113 reviews
Positive73.5%
Neutral8.0%
Negative18.6%

Bugs and requests

JSCalculator

Not enough reviews yet to summarise bugs or requests.

Time Left

Reported bugs

9 issues
  • Widget not updating daily after recent updates
  • Display text rendering issues (font size problems)
  • App fails to load past welcome screen on some devices
  • Widget incompatibility with iOS 18.4
  • Years and months numbers displaying upside down
Show 4 more
  • Days not appearing in display
  • Laggy page transitions
  • Current day needle stuck and not moving
  • Developer unresponsive to support requests

Requested features

11 requests
  • Lock screen widget support
  • Apple Watch widget integration
  • Multiple time granularity options (weeks, days, hours)
  • Life expectancy limit increased beyond 90 years
  • Customizable row lengths in calendar view
Show 6 more
  • Auto dark mode for app and widgets
  • Specific date countdown feature
  • Weekly and monthly visualization options
  • Ability to adjust widget size and display metrics
  • Calendar view showing weeks per year
  • Pan and zoom functionality for overall view

In-app purchases

None

JSCalculator

No in-app purchases

5 purchases

Time Left

Subscriptions3
  • Per week$4.997 Days
  • Annual3 Days trial$17.991 Year
  • Per year$17.991 Year
One-time2
  • Lifetime$19.99
  • One time$24.99

Questions

Is JSCalculator free?
JSCalculator costs $0.99, with no in-app purchases.
Is Time Left free?
Time Left is free to download, with in-app purchases available.
Which has better reviews, JSCalculator or Time Left?
JSCalculator is rated higher. JSCalculator averages 5.0 out of 5 from 2 ratings, while Time Left averages 4.6 from 237 ratings.
Do JSCalculator or Time Left have ads?
Neither JSCalculator nor Time Left shows ads.
Which is updated more often, JSCalculator or Time Left?
JSCalculator ships an update every 25 months, and Time Left every 6 days. Most recently, JSCalculator was updated on October 3, 2026 and Time Left on October 20, 2026.

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