# 三元催化风向标 vs 制选

The clearest difference is update cadence: 制选 at fortnightly against 三元催化风向标's every 2 months. On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. 三元催化风向标 sells 10 one-off in-app purchases and 制选 sells 2 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.

三元催化风向标 ships an update every 2 months, 制选 fortnightly. The most recent releases landed on September 8, 2026 and October 16, 2026 respectively.

## The numbers

| Metric | 三元催化风向标 | 制选 |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | Yes | Yes |
| Update frequency | Every 2 months | **Fortnightly** |
| Size | 35 MB | 95 MB |
| Requires iOS | 13.0 | **12.0** |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 12+ |
| Developer | [Shenzhen Youyu Technology Co., Ltd.](https://appshunter.io/developer/1190014252) | [723340075](https://appshunter.io/developer/1568054323) |

## What reviewers say

### 三元催化风向标

[App page](https://appshunter.io/ios/app/id1542725614)

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

**In-app purchases (10)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Plus体验卡1天 | $3.99 | one-time |
| 初级 66次(3个月) | $19.99 | one-time |
| 初级 300次(1年) | $59.99 | one-time |
| 团队版(1个月) | $69.99 | one-time |
| 专业版Plus（2个月） | $99.99 | one-time |
| 团队版(2个月) | $129.99 | one-time |
| 专业版Plus（半年） | $249.99 | one-time |
| 团队版(半年) | $349.99 | one-time |
| 专业版Plus（1年） | $499.99 | one-time |
| 团队版（一年） | $599.99 | one-time |


### 制选

[App page](https://appshunter.io/ios/app/id1568054321)

**Features:** macOS Compatibility

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 30天展商资格 | $89.99 | one-time |
| 7天轮播图展示 | $249.99 | one-time |


## Frequently asked questions

### Is 三元催化风向标 free?

三元催化风向标 is free to download, with in-app purchases available.

### Is 制选 free?

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

### Do 三元催化风向标 or 制选 have ads?

Both 三元催化风向标 and 制选 show ads.

### Which is updated more often, 三元催化风向标 or 制选?

三元催化风向标 ships an update every 2 months, and 制选 fortnightly. Most recently, 三元催化风向标 was updated on September 8, 2026 and 制选 on October 16, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*