# TC Mobile I/O vs whatwatt

The clearest difference is update cadence: whatwatt at every 2 weeks against TC Mobile I/O's every 28 months. TC Mobile I/O's advantage is iOS requirement (11.0.0 vs 17.0). On price, review sentiment, ads and in-app purchases there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

TC Mobile I/O ships an update every 28 months, whatwatt every 2 weeks. The most recent releases landed on November 2, 2026 and November 4, 2026 respectively.

## The numbers

| Metric | TC Mobile I/O | whatwatt |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/whatwatt/id6740263482/reviews)** |
| Number of ratings | — | **1** |
| Positive reviews | 100.0% of reviews | 100.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 28 months | **Every 2 weeks** |
| Monetization | Free | Free |
| Size | 12 MB | 53 MB |
| Requires iOS | **11.0.0** | 17.0 |
| Devices | iPhone, iPod | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Phoenix Contact GmbH & Co. KG](https://appshunter.io/developer/426916392) | [whatwatt AG](https://appshunter.io/developer/1789292734) |

## What reviewers say

### TC Mobile I/O

[App page](https://appshunter.io/ios/app/tc-mobile-io/id1139160079)

Control your TC MOBILE I/O X200 SMS relay with this application. It displays device status and sends commands, eliminating the need for manual SMS writing. Access datasheets and switch between German and English languages.

**Highlights:** Device status indication, Send switching commands, Eliminates manual SMS writing, Data sheet download, Multilingual support (German, English)

**Features:** macOS Compatibility

**In-app purchases:** none


### whatwatt

[App page](https://appshunter.io/ios/app/whatwatt/id6740263482)

This utility app is preparing for future enhancements. Developers are working on new functionalities that will be revealed soon.

**Highlights:** Future feature groundwork, Upcoming enhancements, Developer updates

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

**In-app purchases:** none


## Frequently asked questions

### Is TC Mobile I/O free?

TC Mobile I/O is free to download, with no in-app purchases.

### Is whatwatt free?

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

### Do TC Mobile I/O or whatwatt have ads?

Neither TC Mobile I/O nor whatwatt shows ads.

### Which is updated more often, TC Mobile I/O or whatwatt?

TC Mobile I/O ships an update every 28 months, and whatwatt every 2 weeks. Most recently, TC Mobile I/O was updated on November 2, 2026 and whatwatt on November 4, 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.*