# FDS Smart Chrono vs TM550

The clearest difference is in-app purchases: TM550 at none against FDS Smart Chrono's 2. TM550 also leads on device support (3 vs 1) and iOS requirement (12.0 vs 15.6). On price, update cadence and ads there is nothing between them.

Both are free to download. FDS Smart Chrono sells 2 one-off in-app purchases. TM550 asks for nothing beyond the download.

Both ship on a similar rhythm, roughly every 2 months. The most recent releases landed on October 26, 2026 and October 27, 2026 respectively.

## The numbers

| Metric | FDS Smart Chrono | TM550 |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 2 months | Every 2 months |
| Size | 45 MB | 42 MB |
| Requires iOS | 15.6 | **12.0** |
| Devices | iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [FDS-Timing Sarl](https://appshunter.io/developer/1208225025) | [ITS-CHRONO](https://appshunter.io/developer/1278336293) |

## What reviewers say

### FDS Smart Chrono

[App page](https://appshunter.io/ios/app/fds-smart-chrono/id1271365456)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 1 Year Subscription | $59.99 | one-time |
| 1 Year Subscription | $79.99 | one-time |


### TM550

[App page](https://appshunter.io/ios/app/tm550/id1659378867)

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

**In-app purchases:** none


## Frequently asked questions

### Is FDS Smart Chrono free?

FDS Smart Chrono is free to download, with in-app purchases available.

### Is TM550 free?

TM550 is free to download, with no in-app purchases.

### Do FDS Smart Chrono or TM550 have ads?

Neither FDS Smart Chrono nor TM550 shows ads.

### Which is updated more often, FDS Smart Chrono or TM550?

FDS Smart Chrono ships an update every 2 months, and TM550 every 2 months. Most recently, FDS Smart Chrono was updated on October 26, 2026 and TM550 on October 27, 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.*