# 极牙 vs Aligner Tracker

The clearest difference is in-app purchases: 极牙 at none against Aligner Tracker's 9. 极牙 also leads on iOS requirement (13.0 vs 16.4). Aligner Tracker's advantage is update cadence (every 5 weeks vs every 4 months). On price, ads and device support there is nothing between them.

Both are free to download. Aligner Tracker sells 9 in-app purchases, starting at $1.99 per 7 days. 极牙 asks for nothing beyond the download.

极牙 ships an update every 4 months, Aligner Tracker every 5 weeks. The most recent releases landed on October 25, 2026 and October 30, 2026 respectively.

## The numbers

| Metric | 极牙 | Aligner Tracker |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[4.2 (29 ratings)](https://appshunter.io/ios/app/aligner-tracker-traytrack/id6753336549/reviews)** |
| Number of ratings | — | **29** |
| Positive reviews | — | 66.7% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 4 months | **Every 5 weeks** |
| Monetization | — | Freemium |
| Size | 43 MB | 103 MB |
| Requires iOS | **13.0** | 16.4 |
| Devices | iPhone, iPod | iPhone, Apple Watch |
| Age rating | 4+ | 12+ |
| Developer | [Nanjing qianzhige Information Technology Co., Ltd](https://appshunter.io/developer/1625451175) | [RSApps Nordics](https://appshunter.io/developer/1745539685) |

## What reviewers say

### 极牙

[App page](https://appshunter.io/ios/app/id1625451173)

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

**In-app purchases:** none


### Aligner Tracker

[App page](https://appshunter.io/ios/app/aligner-tracker-traytrack/id6753336549)

This app helps you track your clear aligner wear time with an intuitive timer and provides reminders for switching to the next tray. It visually displays your progress towards achieving a straighter smile, simplifying your orthodontic journey.

**Highlights:** Intuitive wear time tracking, Smart push notification reminders, Calendar view for tray schedule, Apple Watch app integration, Siri Shortcuts support, Lock screen and Home screen widgets, Live Activity support

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

**In-app purchases (9)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Plus | $1.99 | per 7 days |
| Plus | $4.99 | per month |
| Plus | $19.99 | per year |
| Plus | $24.99 | per year |
| Plus | $29.99 | per year |
| Plus | $34.99 | per year |
| Plus | $34.99 | per year |
| TrayTrack Plus | $29.99 | one-time |
| TrayTrack Plus | $59.99 | one-time |


## Frequently asked questions

### Is 极牙 free?

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

### Is Aligner Tracker free?

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

### Do 极牙 or Aligner Tracker have ads?

Neither 极牙 nor Aligner Tracker shows ads.

### Which is updated more often, 极牙 or Aligner Tracker?

极牙 ships an update every 4 months, and Aligner Tracker every 5 weeks. Most recently, 极牙 was updated on October 25, 2026 and Aligner Tracker 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.*