# Rex vs KotoVelluna

The clearest difference is update cadence: Rex at every 4 days against KotoVelluna's every 3 weeks. KotoVelluna's advantage is iOS requirement (13.0 vs 18.6). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Rex sells 2 in-app purchases, starting at $11.99 per month and KotoVelluna sells 2 in-app purchases, starting at $1.99 per month. Whichever you choose, the download price is not the number that matters.

Rex ships an update every 4 days, KotoVelluna every 3 weeks. The most recent releases landed on October 9, 2026 and October 11, 2026 respectively.

## The numbers

| Metric | Rex | KotoVelluna |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/rex-study-smarter/id6775703977/reviews)** | — |
| Number of ratings | **1** | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | **Every 4 days** | Every 3 weeks |
| Monetization | Free with in-app purchases | — |
| Size | 80 MB | 157 MB |
| Requires iOS | 18.6 | **13.0** |
| Devices | iPhone, iPad, Mac | iPhone, iPad, iPod |
| Age rating | 12+ | 4+ |
| Developer | [Oran Egbuchunam](https://appshunter.io/developer/6775544967) | [masahiro ito](https://appshunter.io/developer/6801775184) |

## What reviewers say

### Rex

[App page](https://appshunter.io/ios/app/rex-study-smarter/id6775703977)

This app offers an interactive learning experience by explaining concepts aloud and allowing users to manipulate 3D models and live charts. It consolidates notes, PDFs, and web research onto a single canvas and supports collaborative study sessions.

**Highlights:** Voice explanations of questions, Interactive 3D scenes and live charts, Consolidated study canvas, Lecture transcription and note-taking, Read-aloud functionality for notes and PDFs, Language practice with real scenes, Live collaborative study boards

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Pro | $11.99 | per month |
| Rex Pro Annual | $99.99 | per year |


### KotoVelluna

[App page](https://appshunter.io/ios/app/kotovelluna/id6803022607)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly Premium | $1.99 | per month |
| Yearly Premium | $17.99 | per year |


## Frequently asked questions

### Is Rex free?

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

### Is KotoVelluna free?

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

### Do Rex or KotoVelluna have ads?

Neither Rex nor KotoVelluna shows ads.

### Which is updated more often, Rex or KotoVelluna?

Rex ships an update every 4 days, and KotoVelluna every 3 weeks. Most recently, Rex was updated on October 9, 2026 and KotoVelluna on October 11, 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.*