# IUSS vs tdc.

The clearest difference is update cadence: tdc. at every 2 weeks against IUSS's every 4 months. IUSS's advantage is iOS requirement (12.0 vs 15.1). On price, ads, in-app purchases and device support there is nothing between them.

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

IUSS ships an update every 4 months, tdc. every 2 weeks. The most recent releases landed on October 8, 2026 and October 28, 2026 respectively.

## The numbers

| Metric | IUSS | tdc. |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 4 months | **Every 2 weeks** |
| Size | 102 MB | 101 MB |
| Requires iOS | **12.0** | 15.1 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [CodeHEX Solutions](https://appshunter.io/developer/1653264459) | [Abdul Majid Shah Bukhari](https://appshunter.io/developer/1896112171) |

## What reviewers say

### IUSS

[App page](https://appshunter.io/ios/app/iuss-pupilsoft/id6444241949)

**Features:** macOS Compatibility

**In-app purchases:** none


### tdc.

[App page](https://appshunter.io/ios/app/tdc/id6765877675)

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

**In-app purchases:** none


## Frequently asked questions

### Is IUSS free?

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

### Is tdc. free?

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

### Do IUSS or tdc. have ads?

Neither IUSS nor tdc. shows ads.

### Which is updated more often, IUSS or tdc.?

IUSS ships an update every 4 months, and tdc. every 2 weeks. Most recently, IUSS was updated on October 8, 2026 and tdc. on October 28, 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.*