# Pool Doctor vs Calendar Clock

The clearest difference is review sentiment: Pool Doctor at 68% against Calendar Clock's 0%. Pool Doctor also leads on update cadence (every 2 months vs every 41 months) and iOS requirement (11.0 vs 26.5). Calendar Clock's advantage is price ($0.99 vs $19.99). On ads, in-app purchases, monetization model and device support there is nothing between them.

Pool Doctor costs $19.99 and Calendar Clock $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Pool Doctor ships an update every 2 months, Calendar Clock every 41 months. The most recent releases landed on October 23, 2026 and October 15, 2026 respectively.

## The numbers

| Metric | Pool Doctor | Calendar Clock |
| --- | --- | --- |
| Price | $19.99 | **$0.99** |
| Rating | **[4.4 (134 ratings)](https://appshunter.io/ios/app/pool-doctor/id375459618/reviews)** | — |
| Number of ratings | **134** | — |
| Positive reviews | **67.8% of reviews** | 0.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 2 months** | Every 41 months |
| Monetization | Paid | Paid |
| Size | 7 MB | 4 MB |
| Requires iOS | **11.0** | 26.5 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Gazzini Ventures](https://appshunter.io/developer/1503581197) | [Systemiko Inc.](https://appshunter.io/developer/680630947) |

## What reviewers say

### Pool Doctor

[App page](https://appshunter.io/ios/app/pool-doctor/id375459618)

This powerful digital tool helps pool professionals and enthusiasts maintain their pools. Input your chemical readings, and it will provide precise instructions on what chemicals to add and why, supporting various pool types and units of measurement.

**Highlights:** Chemical level adjustment (chlorine, pH, alkalinity, etc.), Supports regular, salt-water, and bromine pools, Multiple unit of measurement options, Customizable ideal ranges and chemicals, Saves reading and treatment records, Langelier Index calculation, Shock calculator

**Features:** macOS Compatibility

**In-app purchases:** none

**What reviewers like**

- 👍 Easy to use and intuitive interface
- 🎯 Accurate chemical calculations and recommendations
- 💡 Customizable pool parameters and chemical selection
- 📊 Helpful for pool maintenance beginners
- 🔄 Multiple unit conversions (lbs, oz, kg, metric)

**What reviewers complain about**

- 🐛 App crashes frequently
- ❌ Email functionality doesn't work
- ⚠️ Inaccurate recommendations for some pool types
- 🔧 Settings don't persist or sync across devices
- 💸 Price increased from free to $20

**Reported bugs**

- App crashes after entering readings
- Phone keyboard won't close, preventing navigation
- Entered values change automatically (pH decreases, chlorine increases)
- Chemical settings don't save or remember user preferences
- Recommendations ignore user-specified chemical concentrations

**Requested features**

- Customizable input field order to match test kit order
- Support for Baquacil pool products
- Cyanuric acid reading support
- Ability to select specific chemical types (liquid vs powdered chlorine)
- Salt level adjustment based on salt water generator (SWG) ranges


### Calendar Clock

[App page](https://appshunter.io/ios/app/calendar-clock/id1451445740)

This app displays the current year, month, week, and time on a single screen with a clean design. It offers customizable theme colors and functions as a desk clock. The app disables device sleep mode while active.

**Highlights:** All-in-one screen display, Year, month, week, day, hour, minute, second, Switchable theme colors (dark, light, green, blue), Disables device sleep mode, Acts as a desk clock

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Pool Doctor free?

Pool Doctor costs $19.99, with no in-app purchases.

### Is Calendar Clock free?

Calendar Clock costs $0.99, with no in-app purchases.

### Do Pool Doctor or Calendar Clock have ads?

Neither Pool Doctor nor Calendar Clock shows ads.

### Which is updated more often, Pool Doctor or Calendar Clock?

Pool Doctor ships an update every 2 months, and Calendar Clock every 41 months. Most recently, Pool Doctor was updated on October 23, 2026 and Calendar Clock on October 15, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*