# Tobi app vs Echo Calculate

The clearest difference is in-app purchases: Tobi app at none against Echo Calculate's 1. Tobi app also leads on update cadence (every 2 months vs every 6 months). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Echo Calculate sells 1 one-off in-app purchase. Tobi app asks for nothing beyond the download.

Tobi app ships an update every 2 months, Echo Calculate every 6 months. The most recent releases landed on September 17, 2026 and September 16, 2026 respectively.

## The numbers

| Metric | Tobi app | Echo Calculate |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 2 months** | Every 6 months |
| Size | 37 MB | 26 MB |
| Requires iOS | 16.6 | **15.6** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 12+ | 4+ |
| Developer | [The Medical University of South Carolina](https://appshunter.io/developer/1503987548) | [Gundogan Emre](https://appshunter.io/developer/1651146056) |

## What reviewers say

### Tobi app

[App page](https://appshunter.io/ios/app/tobi-app/id1605608449)

**Features:** macOS Compatibility

**In-app purchases:** none


### Echo Calculate

[App page](https://appshunter.io/ios/app/echo-calculate/id1660468437)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Echo Calculate Premium | $3.99 | one-time |


## Frequently asked questions

### Is Tobi app free?

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

### Is Echo Calculate free?

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

### Do Tobi app or Echo Calculate have ads?

Neither Tobi app nor Echo Calculate shows ads.

### Which is updated more often, Tobi app or Echo Calculate?

Tobi app ships an update every 2 months, and Echo Calculate every 6 months. Most recently, Tobi app was updated on September 17, 2026 and Echo Calculate on September 16, 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.*