# ThinkOnTheFly vs Xi Yun

The clearest difference is iOS requirement: Xi Yun at 15 against ThinkOnTheFly's 17.6. On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. ThinkOnTheFly sells 3 in-app purchases, starting at $0.99 per month and Xi Yun sells 12 in-app purchases, starting at $8.99 per 7 days. Whichever you choose, the download price is not the number that matters.

ThinkOnTheFly ships an update fortnightly, Xi Yun every 9 days. The most recent releases landed on October 18, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | ThinkOnTheFly | Xi Yun |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Fortnightly | **Every 9 days** |
| Size | 10 MB | 145 MB |
| Requires iOS | 17.6 | **15** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 17+ |
| Developer | [家贺 万](https://appshunter.io/developer/1820076368) | [XIYUN TECHNOLOGY LIMITED](https://appshunter.io/developer/1842024987) |

## What reviewers say

### ThinkOnTheFly

[App page](https://appshunter.io/ios/app/thinkonthefly/id6747250744)

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly Plan | $0.99 | per month |
| Annual Plan | $2.99 | per year |
| Lifetime Access | $5.99 | one-time |


### Xi Yun

[App page](https://appshunter.io/ios/app/xi-yun/id6754867283)

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

**In-app purchases (12)**

| Purchase | Price | Billing |
| --- | --- | --- |
| VIP | $8.99 | per 7 days |
| svip | $18.99 | per month |
| SSVIP | $69.99 | per year |
| Sui xi 1 | $2.99 | one-time |
| 5 consultation sessions | $2.99 | one-time |
| 10 Consultation Sessions | $4.99 | one-time |
| Sui xi 2 | $6.99 | one-time |
| 15 consultation sessions | $6.99 | one-time |
| Sui xi 3 | $9.99 | one-time |
| Astrology analysis | $59.99 | one-time |
| Online feng shui | $129.99 | one-time |
| Feng shui layout | $299.99 | one-time |


## Frequently asked questions

### Is ThinkOnTheFly free?

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

### Is Xi Yun free?

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

### Do ThinkOnTheFly or Xi Yun have ads?

Neither ThinkOnTheFly nor Xi Yun shows ads.

### Which is updated more often, ThinkOnTheFly or Xi Yun?

ThinkOnTheFly ships an update fortnightly, and Xi Yun every 9 days. Most recently, ThinkOnTheFly was updated on October 18, 2026 and Xi Yun on October 25, 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.*