# VU biblioteka vs Rainbow Challenge App

The clearest difference is update cadence: VU biblioteka at every 10 days against Rainbow Challenge App's every 32 months. Rainbow Challenge App's advantage is iOS requirement (12.0 vs 15.6). 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.

VU biblioteka ships an update every 10 days, Rainbow Challenge App every 32 months. The most recent releases landed on October 16, 2026 and October 7, 2026 respectively.

## The numbers

| Metric | VU biblioteka | Rainbow Challenge App |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 10 days** | Every 32 months |
| Size | 3 MB | 42 MB |
| Requires iOS | 15.6 | **12.0** |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 12+ |
| Developer | [Vilnius University](https://appshunter.io/developer/1435474400) | [TOLERANTISKO JAUNIMO ASOCIACIJA](https://appshunter.io/developer/1653302851) |

## What reviewers say

### VU biblioteka

[App page](https://appshunter.io/ios/app/vu-biblioteka/id1435474401)

**Features:** macOS Compatibility

**In-app purchases:** none


### Rainbow Challenge App

[App page](https://appshunter.io/ios/app/rainbow-challenge-app/id6444240926)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is VU biblioteka free?

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

### Is Rainbow Challenge App free?

Rainbow Challenge App is free to download, with no in-app purchases.

### Do VU biblioteka or Rainbow Challenge App have ads?

Neither VU biblioteka nor Rainbow Challenge App shows ads.

### Which is updated more often, VU biblioteka or Rainbow Challenge App?

VU biblioteka ships an update every 10 days, and Rainbow Challenge App every 32 months. Most recently, VU biblioteka was updated on October 16, 2026 and Rainbow Challenge App on October 7, 2026.

---

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