# Fello AI vs K2Sonnet

The clearest difference is in-app purchases: K2Sonnet at none against Fello AI's 7. Fello AI's advantage is update cadence (every 10 days vs every 7 months). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Fello AI sells 7 in-app purchases, starting at $4.99 per 7 days. K2Sonnet asks for nothing beyond the download.

Fello AI ships an update every 10 days, K2Sonnet every 7 months. The most recent releases landed on October 18, 2026 and October 2, 2026 respectively.

## The numbers

| Metric | Fello AI | K2Sonnet |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.6 (127 ratings)](https://appshunter.io/ios/app/fello-ai-chat-bot-assistant/id6447705369/reviews)** | — |
| Number of ratings | **127** | — |
| Positive reviews | 66.5% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 10 days** | Every 7 months |
| Monetization | Freemium | — |
| Size | 49 MB | 2 MB |
| Requires iOS | **16.0** | 17.6 |
| Devices | **iPhone, iPad, Mac** | iPhone, iPad |
| Age rating | 12+ | 17+ |
| Developer | [AI Apps Brewery s.r.o.](https://appshunter.io/developer/1538055054) | [Shanghai Jiyue Information Technology Co., Ltd.](https://appshunter.io/developer/1795192424) |

## What reviewers say

### Fello AI

[App page](https://appshunter.io/ios/app/fello-ai-chat-bot-assistant/id6447705369)

This AI assistant integrates multiple advanced language and image models into a single application. It allows users to chat with files, generate documents, spreadsheets, presentations, and images, and search the web with cited sources. Available across Apple devices, it offers a free tier with limited messages and a subscription for unlimited access.

**Highlights:** Access multiple AI models in one app, Create .pptx, .xlsx, .docx, and .pdf files, Chat with files and images, Generate and edit AI images, Web search with cited sources, Syncs across Mac, iPhone, and iPad, Organized with pins and bookmarks

**Features:** Vision Pro support

**In-app purchases (7)**

| Purchase | Price | Billing |
| --- | --- | --- |
| AI Chatbot Weekly Plan | $4.99 | per 7 days |
| AI Chatbot Monthly Plan | $11.99 | per month |
| Fello AI Monthly Contribution | $11.99 | per month |
| AI Chatbot Monthly Plan | $11.99 | per month |
| AI Chatbot Quarterly Plan | $24.99 | per 3 months |
| AI Chatbot Yearly Plan | $89.99 | per year |
| AI Chatbot Yearly Plan | $89.99 | per year |


### K2Sonnet

[App page](https://appshunter.io/ios/app/k2sonnet/id6753734747)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Fello AI free?

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

### Is K2Sonnet free?

K2Sonnet is free to download, with no in-app purchases.

### Do Fello AI or K2Sonnet have ads?

Neither Fello AI nor K2Sonnet shows ads.

### Which is updated more often, Fello AI or K2Sonnet?

Fello AI ships an update every 10 days, and K2Sonnet every 7 months. Most recently, Fello AI was updated on October 18, 2026 and K2Sonnet on October 2, 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.*