# 100ls vs LetzFly Ground School

The clearest difference is update cadence: LetzFly Ground School at every 5 days against 100ls's fortnightly. On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. 100ls sells 3 in-app purchases, starting at $4.99 per month and LetzFly Ground School sells 10 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.

100ls ships an update fortnightly, LetzFly Ground School every 5 days. Both last shipped on October 31, 2026.

## The numbers

| Metric | 100ls | LetzFly Ground School |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Fortnightly | **Every 5 days** |
| Size | 15 MB | 188 MB |
| Requires iOS | 18.0 | **17.0** |
| Devices | iPhone | **iPhone, iPad** |
| Age rating | 12+ | 4+ |
| Developer | [Socratop Tech](https://appshunter.io/developer/1815862937) | [NeatCapital OU](https://appshunter.io/developer/841531887) |

## What reviewers say

### 100ls

[App page](https://appshunter.io/ios/app/100ls/id6760612392)

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 100ls plus monthly | $4.99 | per month |
| 100ls plus yearly | $39.99 | per year |
| 100ls 终身会员 | $39.99 | one-time |


### LetzFly Ground School

[App page](https://appshunter.io/ios/app/letzfly-ground-school/id6768289173)

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

**In-app purchases (10)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Air Law | $5.99 | one-time |
| Aircraft General Knowledge | $5.99 | one-time |
| Flight Performance and Planning | $5.99 | one-time |
| Human Performance | $5.99 | one-time |
| Meteorology | $5.99 | one-time |
| Navigation | $5.99 | one-time |
| Operational Procedures | $5.99 | one-time |
| Principles of Flight | $5.99 | one-time |
| Communications | $5.99 | one-time |
| Unlock All Topics | $29.99 | one-time |


## Frequently asked questions

### Is 100ls free?

100ls is free to download, with in-app purchases available.

### Is LetzFly Ground School free?

LetzFly Ground School is free to download, with in-app purchases available.

### Do 100ls or LetzFly Ground School have ads?

Neither 100ls nor LetzFly Ground School shows ads.

### Which is updated more often, 100ls or LetzFly Ground School?

100ls ships an update fortnightly, and LetzFly Ground School every 5 days. Most recently, 100ls was updated on October 31, 2026 and LetzFly Ground School on October 31, 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.*