# 環境・公害系資格　統合版 vs Cat's Study

The clearest difference is price: Cat's Study at Free against 環境・公害系資格　統合版's $4.99. Cat's Study also leads on update cadence (every 4 days vs every 56 months) and review sentiment (100% vs 75%). 環境・公害系資格　統合版's advantage is in-app purchases (none vs 6) and ads (none vs shown). On device support and iOS requirement there is nothing between them.

Cat's Study is free to download; 環境・公害系資格　統合版 costs $4.99 up front. Cat's Study sells 6 in-app purchases, starting at $2.49 per month. 環境・公害系資格　統合版 asks for nothing beyond the download.

環境・公害系資格　統合版 ships an update every 56 months, Cat's Study every 4 days. The most recent releases landed on November 11, 2026 and November 10, 2026 respectively.

## The numbers

| Metric | 環境・公害系資格　統合版 | Cat's Study |
| --- | --- | --- |
| Price | $4.99 | **Free** |
| Positive reviews | 75.0% of reviews | **100.0% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 56 months | **Every 4 days** |
| Monetization | — | Free with in-app purchases |
| Size | 68 MB | 210 MB |
| Requires iOS | **15.0** | 16.6 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 17+ | 4+ |
| Developer | [harada keiko](https://appshunter.io/developer/1457179049) | [Lo-Fi Labs Inc.](https://appshunter.io/developer/6796905768) |

## What reviewers say

### 環境・公害系資格　統合版

[App page](https://appshunter.io/ios/app/id1487273459)

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


### Cat's Study

[App page](https://appshunter.io/ios/app/cats-study-focus-timer/id6816829300)

Enhance your focus with a charming virtual cat companion. This app offers customizable Pomodoro timers, task planning, and progress tracking. Personalize your study space with various themes and sounds, and connect with friends for collaborative focus sessions.

**Highlights:** Customizable Pomodoro and stopwatch timers, Task planning and scheduling, Focus time tracking and statistics, Themable rooms and ambient sounds, Social focus sessions with friends and crews, Cat and room customization

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (6)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Cat's Study Pro Monthly | $2.49 | per month |
| Cat's Study Pro Annual | $14.49 | per year |
| 100 Coins | $1.49 | one-time |
| 500 Coins | $6.49 | one-time |
| 1,000 Coins | $9.99 | one-time |
| Cat's Study Pro Lifetime | $33.49 | one-time |


## Frequently asked questions

### Is 環境・公害系資格　統合版 free?

環境・公害系資格　統合版 costs $4.99, with no in-app purchases.

### Is Cat's Study free?

Cat's Study is free to download, with in-app purchases available.

### Do 環境・公害系資格　統合版 or Cat's Study have ads?

Cat's Study shows ads; 環境・公害系資格　統合版 does not.

### Which is updated more often, 環境・公害系資格　統合版 or Cat's Study?

環境・公害系資格　統合版 ships an update every 56 months, and Cat's Study every 4 days. Most recently, 環境・公害系資格　統合版 was updated on November 11, 2026 and Cat's Study on November 10, 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.*