Calculi vs Simpool Tech
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Calculi
A smart and powerful calculator designed for ease of use, offering advanced scientific functions, unit and currency conversion, and a supercharged history tape. It adapts to various devices and supports external keyboards for enhanced functionality.
- Complex expression solving
- Unit conversion (17 categories)
- Currency conversion (30+ currencies)
- Scientific constants
- Supercharged history tape
- iMessage app integration
- Apple Watch app
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Calculators can be hard to use. Calculi plans to change all that. SIMPLE BUT POWERFUL Calculi is a smart calculator that is simple and easy to use, but with advanced features for power users. Whether you are trying to balance your checkbook or taking an advanced math class, this app will help you with all of your calculating needs. CALCULATE ANYTHING Calculi doesn’t just add two numbers together but can solve complex expressions using the order of operations. The multi-line display allows for small or large expressions. So go ahead and calculate anything and everything! Press the 2nd button to reveal more scientific functions. UNIT CONVERSION You can easily convert any of your calculations to a different unit across 17 categories such as length, area, and volume. Unit conversions are saved to your calculation history for easy review. A Calculi Pro subscription is required for this feature. CURRENCY CONVERSION Traveling abroad? Not sure how much your lunch costs? Calculi has you covered with support for over 30 different currencies around the globe (data is updated daily from the European Central Bank). A Calculi Pro subscription is required for this feature. CONSTANTS Common constants from both mathematical and scientific fields (astronomical, chemical, electromagnetic, etc.) are included for use in calculations. DESIGNED WITH iOS 18 AND iPadOS 18 IN MIND Calculi adapts to all the latest iOS and iPadOS devices. Even better, multitasking and multi-window support is available in all orientations on the iPad. Interactive widgets are included for calculations on your home screen, and Control Center widgets provide quick access. You can have Calculi wherever you need it. GESTURES Gestures are fun. So why not? - Long press the delete button to clear the display - Long press the equals button to use the previous result or expression - Long press the display to copy, paste, or share - Long press any calculation item to reuse the expression or result SUPERCHARGED HISTORY TAPE Calculations from the history tape can be bookmarked for later and notes can be added for additional context. You can search across notes, expressions, and answers to find the calculation that you are looking for. GET SHARING Don’t be selfish. This history tape can be shared either as a single thread or the entire tape using numerous methods such as email, messaging, or print. There is also an iMessage app so you can easily send calculations. CALCULATE ON YOUR WRIST Calculi is also available on Apple Watch! Besides a four-function calculator, you will also find a tip calculator and counter. EXTERNAL KEYBOARD AND TRACKPAD SUPPORT Pair an external keyboard or trackpad to gain access to powerful shortcuts and full cursor support. You can hold down the command key on your keyboard to view all the available shortcuts. Finally, if you enjoyed Calculi, please take some time to leave a review. Feedback is always appreciated for future updates. CALCULI PRO This yearly subscription grants you access to the following: - Unit Conversions - Currency Conversions - App Themes - Colorful custom icons TIP JAR If you enjoy using the app and want to support an independent app developer, please consider sending a tip. Subscription Details – 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 Terms of Use: https://www.calculiapp.com/terms.html Privacy Policy: https://www.calculiapp.com/privacy-policy.html
Simpool Tech
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Owning a pool should be relaxing—not another thing on your to-do list. Our app makes it easy to find and sign up for professional pool service right in your neighborhood. Discover pool service companies near you: Instantly see local, vetted pool service providers that operate in your area. Sign up in minutes: Choose your service, select your preferred day of the week, and get started—no phone calls required. Sit back & relax: Your pool gets cleaned on schedule while you enjoy crystal-clear water year-round.
Screenshots
Verdict
The clearest difference is in-app purchases: Simpool Tech at none against Calculi's 4. Simpool Tech also leads on update cadence (every 2 weeks vs every 2 months) and iOS requirement (14.0.0 vs 17.6). On price, ads 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
Both are free to download. Calculi sells 4 in-app purchases, starting at $2.99 per year. Simpool Tech asks for nothing beyond the download.
Calculi ships an update every 2 months, Simpool Tech every 2 weeks. The most recent releases landed on October 22, 2026 and October 16, 2026 respectively.
| Parameter | Calculi | Simpool Tech |
|---|---|---|
| Price | Free | Free |
| Rating | 4.4 (383 ratings) — better | — |
| Positive reviews | 35.3% of reviews | — |
| Number of ratings | 383 — better | — |
| Update frequency | Every 2 months | Every 2 weeks — better |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases | — |
| Devices | iPhone, iPad, Apple TV, Apple Watch — better | iPhone, iPad, iPod |
| Requires iOS | 17.6 | 14.0.0 — better |
| Further details — not scored | ||
| Size | 43 MB | 61 MB |
| Age rating | 4+ | 4+ |
| Developer | Michael Natole, Jr. | Simpool Technologies, LLC |
Bugs and requests
Calculi
Reported bugs
7 issues- Calculation not appearing in history until app restart
- New calculation replaces previous in history tile
- Crashes when multiplying by 1.03
- Physical iPad keyboard not recognized
- App crashes/closes on iPad iOS 13
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- App launches then closes immediately on iOS 13
- Cannot calculate simple equations like 9x9
Requested features
3 requests- Option for Dark Mode all the time
- Option to choose icons
- Fix Slide Over functionality
Simpool Tech
Not enough reviews yet to summarise bugs or requests.
In-app purchases
Calculi
- Calculi Pro3 Days trial$2.991 Year
- Small Tip$0.99
- Medium Tip$2.99
- Large Tip$4.99
Simpool Tech
No in-app purchases









