# DUS Master vs Chain

The clearest difference is in-app purchases: DUS Master at none against Chain's 3. On price, review sentiment, update cadence and ads there is nothing between them.

Both are free to download. Chain sells 3 in-app purchases, starting at $2.99 per month. DUS Master asks for nothing beyond the download.

DUS Master ships an update every 10 days, Chain weekly. The most recent releases landed on November 4, 2026 and October 30, 2026 respectively.

## The numbers

| Metric | DUS Master | Chain |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/dus-master/id6474985706/reviews)** | — |
| Number of ratings | **1** | — |
| Positive reviews | **90.2% of reviews** | 90.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 10 days | **Weekly** |
| Monetization | **Free** | Freemium |
| Size | 33 MB | 21 MB |
| Requires iOS | **14.0** | 15.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 17+ | 4+ |
| Developer | [Ahmet Ay](https://appshunter.io/developer/1185833917) | [Muhammed Talha POLAT](https://appshunter.io/developer/1731811922) |

## What reviewers say

### DUS Master

[App page](https://appshunter.io/ios/app/dus-master/id6474985706)

This app streamlines the DUS exam preparation and application process. It offers tools for studying, performance analysis, and preference simulation, helping users manage their DUS journey effectively.

**Highlights:** DUS Timer, Study Calendar & Analysis, Study Groups, Performance School, Preference Simulation, Branch Statistics, Score & Ranking Calculation

**Features:** macOS Compatibility

**In-app purchases:** none


### Chain

[App page](https://appshunter.io/ios/app/chain-habit-tracker-and-streak/id6478146486)

This app helps you build positive habits and break negative ones through a visual tracking system. Set goals, monitor daily progress, and receive reminders to stay on track. Customize your experience with themes and gain insights into your long-term progress.

**Highlights:** Build unbreakable habit chains, Daily progress tracking with calendar view, Set and achieve personal goals, Routine loop for habit acquisition, Customizable reminders, Motivational quotes and insights, User-friendly interface with themes

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Chain Pro Access - Monthly | $2.99 | per month |
| Chain Pro Access - Annual | $12.99 | per year |
| Chain Pro Access Lifetime | $24.99 | one-time |


## Frequently asked questions

### Is DUS Master free?

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

### Is Chain free?

Chain is free to download, with in-app purchases available.

### Do DUS Master or Chain have ads?

Neither DUS Master nor Chain shows ads.

### Which is updated more often, DUS Master or Chain?

DUS Master ships an update every 10 days, and Chain weekly. Most recently, DUS Master was updated on November 4, 2026 and Chain on October 30, 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.*