# KnowDay vs Sunja

The clearest difference is in-app purchases: KnowDay at none against Sunja's 2. KnowDay also leads on ads (none vs shown) and update cadence (every 5 weeks vs every 5 months). On price and device support there is nothing between them.

Both are free to download. Sunja sells 2 in-app purchases, starting at $29.99 per month. KnowDay asks for nothing beyond the download.

KnowDay ships an update every 5 weeks, Sunja every 5 months. The most recent releases landed on October 17, 2026 and October 7, 2026 respectively.

## The numbers

| Metric | KnowDay | Sunja |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | **Every 5 weeks** | Every 5 months |
| Size | 67 MB | 70 MB |
| Requires iOS | **15.1** | 17.6 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Daniel Brouwer](https://appshunter.io/developer/1870224712) | [Sunja Labs Private Limited](https://appshunter.io/developer/1774734869) |

## What reviewers say

### KnowDay

[App page](https://appshunter.io/ios/app/knowday/id6758007504)

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

**In-app purchases:** none


### Sunja

[App page](https://appshunter.io/ios/app/sunja-interactive-3d-science/id6760365462)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly Learning | $29.99 | per month |
| Annual Learning | $199.99 | per year |


## Frequently asked questions

### Is KnowDay free?

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

### Is Sunja free?

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

### Do KnowDay or Sunja have ads?

Sunja shows ads; KnowDay does not.

### Which is updated more often, KnowDay or Sunja?

KnowDay ships an update every 5 weeks, and Sunja every 5 months. Most recently, KnowDay was updated on October 17, 2026 and Sunja on October 7, 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.*