# Data Engineer Cert Prep vs CLF

The clearest difference is in-app purchases: Data Engineer Cert Prep at none against CLF's 3. CLF's advantage is update cadence (every 2 months vs every 13 months). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. CLF sells 3 in-app purchases, starting at $3.99 per month. Data Engineer Cert Prep asks for nothing beyond the download.

Data Engineer Cert Prep ships an update every 13 months, CLF every 2 months. The most recent releases landed on October 1, 2026 and September 25, 2026 respectively.

## The numbers

| Metric | Data Engineer Cert Prep | CLF |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 13 months | **Every 2 months** |
| Size | 1 MB | 27 MB |
| Requires iOS | 16.0 | **15.0** |
| Devices | iPhone, iPad, Mac | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [DjamgaTech Corp](https://appshunter.io/developer/969000181) | [Davy Raitt](https://appshunter.io/developer/1795318281) |

## What reviewers say

### Data Engineer Cert Prep

[App page](https://appshunter.io/ios/app/data-engineer-cert-prep/id6566170013)

**Features:** Vision Pro support

**In-app purchases:** none


### CLF

[App page](https://appshunter.io/ios/app/clf-c02-cloud-practitioner/id6746121070)

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Pro Monthly | $3.99 | per month |
| Pro Yearly | $14.99 | per year |
| Pro Lifetime | $19.99 | one-time |


## Frequently asked questions

### Is Data Engineer Cert Prep free?

Data Engineer Cert Prep is free to download, with no in-app purchases.

### Is CLF free?

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

### Do Data Engineer Cert Prep or CLF have ads?

Neither Data Engineer Cert Prep nor CLF shows ads.

### Which is updated more often, Data Engineer Cert Prep or CLF?

Data Engineer Cert Prep ships an update every 13 months, and CLF every 2 months. Most recently, Data Engineer Cert Prep was updated on October 1, 2026 and CLF 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.*