# Did You Know.. vs Unfog

The clearest difference is update cadence: Unfog at every 2 days against Did You Know..'s every 5 days. On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Did You Know.. sells 1 one-off in-app purchase and Unfog sells 3 in-app purchases, starting at $2.99 per 7 days. Whichever you choose, the download price is not the number that matters.

Did You Know.. ships an update every 5 days, Unfog every 2 days. The most recent releases landed on October 15, 2026 and October 17, 2026 respectively.

## The numbers

| Metric | Did You Know.. | Unfog |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/did-you-know/id6761013561/reviews)** | — |
| Number of ratings | **1** | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 5 days | **Every 2 days** |
| Monetization | Free with in-app purchases | — |
| Size | 4 MB | 80 MB |
| Requires iOS | 17.6 | **17.0** |
| Devices | iPhone | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [柏生 杨](https://appshunter.io/developer/1887198371) | [BITSEC SP. Z O.O.](https://appshunter.io/developer/1801990616) |

## What reviewers say

### Did You Know..

[App page](https://appshunter.io/ios/app/did-you-know/id6761013561)

Discover fascinating facts across various subjects in a quick and engaging format. This app delivers bite-sized insights without lengthy reading or pressure, making learning accessible and memorable.

**Highlights:** Short, impactful facts, Bite-sized learning, Covers science, psychology, history, Engaging swipe interface, No long reading required

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Unlock Unlimited Facts | $3.99 | one-time |


### Unfog

[App page](https://appshunter.io/ios/app/unfog-feynman-study-notes/id6776245365)

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Unfog weekly | $2.99 | per 7 days |
| Unfog Monthly | $17.99 | per month |
| Unfog Annual | $29.99 | per year |


## Frequently asked questions

### Is Did You Know.. free?

Did You Know.. is free to download, with in-app purchases available.

### Is Unfog free?

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

### Do Did You Know.. or Unfog have ads?

Neither Did You Know.. nor Unfog shows ads.

### Which is updated more often, Did You Know.. or Unfog?

Did You Know.. ships an update every 5 days, and Unfog every 2 days. Most recently, Did You Know.. was updated on October 15, 2026 and Unfog on October 17, 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.*