# Wattoo vs One SMS

The clearest difference is iOS requirement: One SMS at 15.0 against Wattoo's 17.0. On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. Wattoo sells 2 in-app purchases, starting at $3.99 per month and One SMS sells 10 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.

Wattoo ships an update every 10 days, One SMS every 2 weeks. The most recent releases landed on October 16, 2026 and October 18, 2026 respectively.

## The numbers

| Metric | Wattoo | One SMS |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | **Every 10 days** | Every 2 weeks |
| Size | 10 MB | 37 MB |
| Requires iOS | 17.0 | **15.0** |
| Devices | iPhone, iPad | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Maxime Giraud](https://appshunter.io/developer/1884024361) | [One SMS](https://appshunter.io/developer/6807429114) |

## What reviewers say

### Wattoo

[App page](https://appshunter.io/ios/app/wattoo-calculs-electriques/id6802853643)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Wattoo Pro | $3.99 | per month |
| Wattoo Pro à vie | $34.99 | one-time |


### One SMS

[App page](https://appshunter.io/ios/app/one-sms/id6807429112)

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

**In-app purchases (10)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 10 Ⓐ | $1.19 | one-time |
| 20 Ⓐ | $3.99 | one-time |
| 32 Ⓐ | $4.99 | one-time |
| 55 Ⓐ | $7.99 | one-time |
| 115 Ⓐ | $14.99 | one-time |
| 175 Ⓐ | $22.99 | one-time |
| 240 Ⓐ | $29.99 | one-time |
| 310 Ⓐ | $39.99 | one-time |
| 650 Ⓐ | $79.99 | one-time |
| 1400 Ⓐ | $149.99 | one-time |


## Frequently asked questions

### Is Wattoo free?

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

### Is One SMS free?

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

### Do Wattoo or One SMS have ads?

Neither Wattoo nor One SMS shows ads.

### Which is updated more often, Wattoo or One SMS?

Wattoo ships an update every 10 days, and One SMS every 2 weeks. Most recently, Wattoo was updated on October 16, 2026 and One SMS on October 18, 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.*