# Clean Days vs UnDo

The clearest difference is price: UnDo at Free against Clean Days's $1.99. UnDo also leads on ads (none vs shown) and update cadence (every 5 days vs every 4 months). Clean Days's advantage is device support (3 vs 1) and iOS requirement (15.0 vs 17.6). On in-app purchases there is nothing between them.

UnDo is free to download; Clean Days costs $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Clean Days ships an update every 4 months, UnDo every 5 days. The most recent releases landed on October 16, 2026 and October 8, 2026 respectively.

## The numbers

| Metric | Clean Days | UnDo |
| --- | --- | --- |
| Price | $1.99 | **Free** |
| Positive reviews | 66.7% of reviews | — |
| In-app purchases | No | No |
| Ads | Yes | **No** |
| Update frequency | Every 4 months | **Every 5 days** |
| Monetization | Paid | — |
| Size | 35 MB | 1 MB |
| Requires iOS | **15.0** | 17.6 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 12+ | 4+ |
| Developer | [翠芬 梁](https://appshunter.io/developer/1792659056) | [朝峰 陈](https://appshunter.io/developer/1868597907) |

## What reviewers say

### Clean Days

[App page](https://appshunter.io/ios/app/clean-days/id6746352521)

This app helps users build self-discipline and track personal growth through daily check-ins. Monitor your progress with detailed statistics, earn achievements, and maintain your streak with a user-friendly interface. It's designed to celebrate every step of your journey towards positive change.

**Highlights:** Daily check-ins to track streaks, Detailed statistics and growth trends, Achievement titles for progress, Backfill feature to maintain streaks, Multi-language support, User-friendly interface

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

**In-app purchases:** none


### UnDo

[App page](https://appshunter.io/ios/app/undo/id6761196951)

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

**In-app purchases:** none


## Frequently asked questions

### Is Clean Days free?

Clean Days costs $1.99, with no in-app purchases.

### Is UnDo free?

UnDo is free to download, with no in-app purchases.

### Do Clean Days or UnDo have ads?

Clean Days shows ads; UnDo does not.

### Which is updated more often, Clean Days or UnDo?

Clean Days ships an update every 4 months, and UnDo every 5 days. Most recently, Clean Days was updated on October 16, 2026 and UnDo on October 8, 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.*