Comparison

LSI Pool and Spa Calculator vs MathRoomBuddy

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

Head to head
About

LSI Pool and Spa Calculator

Easily calculate and track the Langelier Saturation Index for your pool water. Maintain optimal water balance for a healthy and safe swimming environment. Supports multiple units and saves your calculations over time.

Highlights
  • LSI Calculation
  • Water Chemistry Tracking
  • Email Calculations
  • CSV Export
  • Offline Use
  • Universal App Support
Features
Read full description

You take pride in caring for pools and spas, and your attention to each reading matters. Thank you for using LSI Pool and Spa Calculator to keep water balance checks, customer details, and service records together. Maintain a pool route, look after a commercial property, or care for your own spa with a water chemistry app that calculates the Langelier Saturation Index and keeps your visit history. Check a result, save the visit, and review the details before your next test. CHECK WATER BALANCE - Calculate LSI using pH, water temperature, calcium hardness, total alkalinity, and total dissolved solids. - See LSI, predicted saturation pH, and a result category. - Review whether your readings indicate a tendency toward scale or corrosion. - Enter temperature in Fahrenheit or Celsius. - Switch units with automatic temperature conversion. - Use the built-in guide to understand the calculation and its inputs. KEEP A SERVICE HISTORY - Save readings under reusable pool, spa, or property names. - Add visit dates and notes about treatments, observations, or follow-up work. - Search records by site, date, notes, or result category. - Sort history to find recent visits or review earlier readings. - Edit saved measurements and recalculate after a correction. - Duplicate a previous record for repeat visits. - Review the selected reading beside your records list on iPad. ORGANIZE CUSTOMERS AND PROPERTIES - Store customer names, companies, phone numbers, email addresses, and notes. - Add contacts manually or choose people to import from device Contacts. - Link several properties to one customer. - Keep a separate address and notes for each site. - Search customer details when you need a phone number or service context. - Edit local customer copies without changing device Contacts. - Keep sites and readings when you remove a customer. FIND SITES ON THE MAP - Open Site Map from Stats to see properties with resolved addresses. - Use the site's address or its linked customer's address. - Tap a pin to open customer details and linked sites. - Find all saved sites in the searchable list, including those awaiting an address. - Add or correct an address and retry its lookup. REVIEW YOUR WATER CHEMISTRY - Compare minimum, maximum, and average readings by site. - View charts for LSI, pH, temperature, calcium hardness, alkalinity, and TDS. - Filter saved readings by result category. - Open a complete reading from Stats when you need the details. - Use sortable spreadsheet review to compare service history. MAKE QUICK CHECKS BETWEEN VISITS - Use Quick Calc without adding a reading to site history. - Keep recent calculator inputs and the latest result on this device. - Reuse values when testing similar water. - Reset the calculator for a fresh check. REPORTS AND BACKUPS - Share a calculation as text or a PDF report. - Export readings, sites, or contacts as CSV files for spreadsheets. - Create PDF reports for your chosen information. - Save a readings backup or a complete backup with customers and site links. - Import a JSON backup while skipping exact duplicates. - Share files through the iPhone and iPad share sheet. Choose Light, Dark, or system appearance and set your preferred temperature units. Habits & Progress lets you set testing goals and review milestones inside the app. Start with up to five saved records in the free version. LSI Pro unlocks a larger record allowance, spreadsheet review, backup import, individual report sharing, and printing. Monthly and lifetime purchase options are available. Use LSI alongside reliable water tests and equipment guidance. Keep measurements, property details, and notes ready for your next service day. Monthly Pro is a 1-month auto-renewable subscription. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

About

MathRoomBuddy

This utility app converts between IEEE floating-point and raw values, as well as hexadecimal and decimal formats. It also functions as a simple RPN calculator.

Highlights
  • IEEE floating-point conversion
  • Hexadecimal to decimal conversion
  • Decimal to hexadecimal conversion
  • RPN calculator functionality
Features
Read full description

This app converts between IEEE floating-point representation and the corresponding raw values. It also converts between hexadecimal and decimal and is a simple RPN calculator.

Screenshots

LSI Pool and Spa Calculator3 screens
MathRoomBuddy3 screens

Verdict

The call

The clearest difference is price: LSI Pool and Spa Calculator at Free against MathRoomBuddy's $0.99. LSI Pool and Spa Calculator also leads on update cadence (every 6 weeks vs every 22 months). MathRoomBuddy's advantage is in-app purchases (none vs 2) and iOS requirement (12.0 vs 17.6). On rating, ratings volume, ads 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

CostPrice · In-app purchases · Ads · Monetization

LSI Pool and Spa Calculator is free to download; MathRoomBuddy costs $0.99 up front. LSI Pool and Spa Calculator sells 2 in-app purchases, starting at $1.99 per month. MathRoomBuddy asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 5.0 for LSI Pool and Spa Calculator against 5.0 for MathRoomBuddy. Both are backed by a comparable volume of ratings — 1 and 2 respectively.

UpkeepUpdate frequency

LSI Pool and Spa Calculator ships an update every 6 weeks, MathRoomBuddy every 22 months. The most recent releases landed on October 23, 2026 and October 20, 2026 respectively.

Scorecard4 real differences · 6 level
LSI Pool and Spa Calculator versus MathRoomBuddy: the parameters behind the verdict, then further details
ParameterLSI Pool and Spa CalculatorMathRoomBuddy
PriceFree — better$0.99
Rating5.0 (1 ratings)5.0 (2 ratings)
Positive reviews75.0% of reviews—
Number of ratings12 — better
Update frequencyEvery 6 weeks — betterEvery 22 months
AdsNoNo
In-app purchasesYesNo — better
MonetizationPaidPaid
DevicesiPhone, iPadiPhone, iPad, iPod — better
Requires iOS17.612.0 — better
Further details — not scored
Size7 MB8 MB
Age rating4+4+
DeveloperVerosocial StudioMike Green

Customer experience

LSI Pool and Spa Calculator

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews12 reviews
Positive75.0%
Neutral8.3%
Negative16.7%

MathRoomBuddy

All ratings2 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

2 purchases

LSI Pool and Spa Calculator

Subscriptions1
  • LSI Calculators pro Monthly$1.991 Month
One-time1
  • LSI Calculators pro lifetime$14.99
None

MathRoomBuddy

No in-app purchases

Questions

Is LSI Pool and Spa Calculator free?
LSI Pool and Spa Calculator is free to download, with in-app purchases available.
Is MathRoomBuddy free?
MathRoomBuddy costs $0.99, with no in-app purchases.
Which has better reviews, LSI Pool and Spa Calculator or MathRoomBuddy?
LSI Pool and Spa Calculator and MathRoomBuddy are both rated 5.0 out of 5 on the App Store, from 1 and 2 ratings respectively.
Do LSI Pool and Spa Calculator or MathRoomBuddy have ads?
Neither LSI Pool and Spa Calculator nor MathRoomBuddy shows ads.
Which is updated more often, LSI Pool and Spa Calculator or MathRoomBuddy?
LSI Pool and Spa Calculator ships an update every 6 weeks, and MathRoomBuddy every 22 months. Most recently, LSI Pool and Spa Calculator was updated on October 23, 2026 and MathRoomBuddy on October 20, 2026.

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