# Dooo vs Syn9

The clearest difference is device support: Dooo at 3 against Syn9's 1. On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. Dooo sells 2 in-app purchases, starting at $0.99 per year and Syn9 sells 6 in-app purchases, starting at $3.00 per month. Whichever you choose, the download price is not the number that matters.

Dooo ships an update every 3 days, Syn9 every 5 days. The most recent releases landed on October 30, 2026 and November 9, 2026 respectively.

## The numbers

| Metric | Dooo | Syn9 |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.5 (2 ratings)](https://appshunter.io/ios/app/dooo-habit-tracker/id6749438072/reviews)** | — |
| Number of ratings | **2** | — |
| Positive reviews | 81.8% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | **Every 3 days** | Every 5 days |
| Monetization | Freemium | — |
| Size | 17 MB | 57 MB |
| Requires iOS | 18.0 | 18.0 |
| Devices | **iPhone, iPad, Apple Watch** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Lovely Duck, LLC](https://appshunter.io/developer/1505160193) | [Tomohiro Sekikawa](https://appshunter.io/developer/1670259539) |

## What reviewers say

### Dooo

[App page](https://appshunter.io/ios/app/dooo-habit-tracker/id6749438072)

Build positive habits effortlessly with this intuitive tracker. Customize goals, view progress with detailed statistics, and stay organized with a to-do list. Syncs across devices and offers a focus mode for enhanced productivity.

**Highlights:** Customizable habit names, icons, and colors, Flexible goal setting with multiple check-in frequencies, Detailed statistics and check-in calendar, To-Do List functionality, Focus mode, iCloud backup and cross-device sync, Data export

**Features:** macOS Compatibility, Apple Watch app, Vision Pro support

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Annual Subscription | $0.99 | per year |
| One-Time Purchase | $2.99 | one-time |


### Syn9

[App page](https://appshunter.io/ios/app/syn9/id6758545066)

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

**In-app purchases (6)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Plus | $3.00 | per month |
| Max | $6.99 | per month |
| Plus annual | $29.00 | per year |
| Light size | $1.99 | one-time |
| Regular size | $3.99 | one-time |
| Generous size | $7.99 | one-time |


## Frequently asked questions

### Is Dooo free?

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

### Is Syn9 free?

Syn9 is free to download, with in-app purchases available.

### Do Dooo or Syn9 have ads?

Neither Dooo nor Syn9 shows ads.

### Which is updated more often, Dooo or Syn9?

Dooo ships an update every 3 days, and Syn9 every 5 days. Most recently, Dooo was updated on October 30, 2026 and Syn9 on November 9, 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.*