# Fermi Practice Drill with AI vs Today Clock

The clearest difference is iOS requirement: Fermi Practice Drill with AI at 16.0 against Today Clock's 18.6. On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. Fermi Practice Drill with AI sells 1 in-app purchase, starting at $5.99 per month and Today Clock sells 4 in-app purchases, starting at $0.49 per month. Whichever you choose, the download price is not the number that matters.

Fermi Practice Drill with AI ships an update every 2 weeks, Today Clock weekly. The most recent releases landed on September 16, 2026 and September 25, 2026 respectively.

## The numbers

| Metric | Fermi Practice Drill with AI | Today Clock |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | Yes | Yes |
| Update frequency | Every 2 weeks | **Weekly** |
| Size | 21 MB | 49 MB |
| Requires iOS | **16.0** | 18.6 |
| Devices | iPhone, iPad | **iPhone, iPad, Apple Watch** |
| Age rating | 4+ | 4+ |
| Developer | [Yuto Inagaki](https://appshunter.io/developer/1733484400) | [Yoshiki Minakata](https://appshunter.io/developer/1799916174) |

## What reviewers say

### Fermi Practice Drill with AI

[App page](https://appshunter.io/ios/app/fermi-practice-drill-with-ai/id6748893807)

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| FerminPro | $5.99 | per month |


### Today Clock

[App page](https://appshunter.io/ios/app/today-clock-analog-clock/id6754206804)

**Features:** macOS Compatibility, Apple Watch app, Vision Pro support

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Today Plus | $0.49 | per month |
| Today Pro | $1.99 | per month |
| Today Plus | $6.99 | per year |
| Today Pro | $19.99 | per year |


## Frequently asked questions

### Is Fermi Practice Drill with AI free?

Fermi Practice Drill with AI is free to download, with in-app purchases available.

### Is Today Clock free?

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

### Do Fermi Practice Drill with AI or Today Clock have ads?

Both Fermi Practice Drill with AI and Today Clock show ads.

### Which is updated more often, Fermi Practice Drill with AI or Today Clock?

Fermi Practice Drill with AI ships an update every 2 weeks, and Today Clock weekly. Most recently, Fermi Practice Drill with AI was updated on September 16, 2026 and Today Clock on September 25, 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.*