# Notes Calculator vs opchat

The clearest difference is update cadence: Notes Calculator at every 3 days against opchat's every 2 weeks. Notes Calculator also leads on iOS requirement (15.0 vs 17.0). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Notes Calculator sells 1 one-off in-app purchase and opchat sells 2 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.

Notes Calculator ships an update every 3 days, opchat every 2 weeks. The most recent releases landed on November 12, 2026 and November 9, 2026 respectively.

## The numbers

| Metric | Notes Calculator | opchat |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[4.0 (2 ratings)](https://appshunter.io/ios/app/opchat-private-on-device-ai/id6761932211/reviews)** |
| Number of ratings | — | **2** |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | **Every 3 days** | Every 2 weeks |
| Monetization | — | Free with in-app purchases |
| Size | 48 MB | 170 MB |
| Requires iOS | **15.0** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 12+ |
| Developer | [Alexandru Florian Mariuti](https://appshunter.io/developer/1299564849) | [Przemyslaw Klosek](https://appshunter.io/developer/1536276533) |

## What reviewers say

### Notes Calculator

[App page](https://appshunter.io/ios/app/notes-calculator/id6504752504)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium — Lifetime | $44.99 | one-time |


### opchat

[App page](https://appshunter.io/ios/app/opchat-private-on-device-ai/id6761932211)

Chat with multiple AI models using your own API keys or run them on your device. Integrates with your calendar, reminders, and productivity apps. Offers custom personas and conversation organization.

**Highlights:** Multi-provider AI chat, On-device model execution, Bring Your Own Key (BYOK), Calendar and reminder integration, Customizable AI personas, Conversation organization and export, Image generation and editing

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Pro Unlock Promo | $9.99 | one-time |
| Pro Unlock | $14.99 | one-time |


## Frequently asked questions

### Is Notes Calculator free?

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

### Is opchat free?

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

### Do Notes Calculator or opchat have ads?

Neither Notes Calculator nor opchat shows ads.

### Which is updated more often, Notes Calculator or opchat?

Notes Calculator ships an update every 3 days, and opchat every 2 weeks. Most recently, Notes Calculator was updated on November 12, 2026 and opchat on November 9, 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.*