# 知虾 vs ROI大师

The clearest difference is in-app purchases: 知虾 at none against ROI大师's 7. On price, update cadence, ads and device support there is nothing between them.

Both are free to download. ROI大师 sells 7 in-app purchases, starting at $0.99 per month. 知虾 asks for nothing beyond the download.

知虾 ships an update monthly, ROI大师 every 2 weeks. The most recent releases landed on October 7, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | 知虾 | ROI大师 |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | — | 25.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Monthly | **Every 2 weeks** |
| Monetization | — | Freemium |
| Size | 39 MB | 63 MB |
| Requires iOS | 13.0 | 13.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [广州萌啦信息科技有限公司](https://appshunter.io/developer/1756891754) | [丹宁 冯](https://appshunter.io/developer/1452086482) |

## What reviewers say

### 知虾

[App page](https://appshunter.io/ios/app/id6535681688)

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

**In-app purchases:** none


### ROI大师

[App page](https://appshunter.io/ios/app/roi/id6743304426)

This tool helps e-commerce operators accurately calculate advertising return on investment (ROI) and optimize pricing strategies. It provides detailed data on ad spend, commissions, profit margins, and break-even points to drive data-informed decisions and reduce wasteful spending.

**Highlights:** Calculate advertising ROI, Optimize product pricing, Analyze ad spend and commissions, Estimate break-even ROI, Simulate costs (logistics, fees), Analyze ad monetization LTV

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

**In-app purchases (7)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 电商ROI计算器月度会员 | $0.99 | per month |
| 电商ROI计算器周度会员 | $0.99 | per 7 days |
| 电商ROI计算器年度会员 | $7.99 | per year |
| 电商ROI计算器周卡会员 | $0.99 | one-time |
| 电商ROI计算器月卡会员 | $2.99 | one-time |
| 电商ROI计算器年卡会员 | $12.99 | one-time |
| 电商ROI计算器终身会员 | $14.99 | one-time |


## Frequently asked questions

### Is 知虾 free?

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

### Is ROI大师 free?

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

### Do 知虾 or ROI大师 have ads?

Neither 知虾 nor ROI大师 shows ads.

### Which is updated more often, 知虾 or ROI大师?

知虾 ships an update monthly, and ROI大师 every 2 weeks. Most recently, 知虾 was updated on October 7, 2026 and ROI大师 on October 24, 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.*