# 現代小數 AR 2 vs RainbowSky

The clearest difference is update cadence: RainbowSky at every 2 weeks against 現代小數 AR 2's every 2 months. On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

現代小數 AR 2 ships an update every 2 months, RainbowSky every 2 weeks. Both last shipped on September 19, 2026.

## The numbers

| Metric | 現代小數 AR 2 | RainbowSky |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 2 weeks** |
| Size | 541 MB | 292 MB |
| Requires iOS | **11.0** | 12.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Modern Educational Research Society, LTD](https://appshunter.io/developer/432268704) | [Open Knowledge Association Ltd.](https://appshunter.io/developer/868011308) |

## What reviewers say

### 現代小數 AR 2

[App page](https://appshunter.io/ios/app/ar-2/id1537758169)

**In-app purchases:** none


### RainbowSky

[App page](https://appshunter.io/ios/app/rainbowsky/id6771268020)

**In-app purchases:** none


## Frequently asked questions

### Is 現代小數 AR 2 free?

現代小數 AR 2 is free to download, with no in-app purchases.

### Is RainbowSky free?

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

### Do 現代小數 AR 2 or RainbowSky have ads?

Neither 現代小數 AR 2 nor RainbowSky shows ads.

### Which is updated more often, 現代小數 AR 2 or RainbowSky?

現代小數 AR 2 ships an update every 2 months, and RainbowSky every 2 weeks. Most recently, 現代小數 AR 2 was updated on September 19, 2026 and RainbowSky on September 19, 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.*