# King vs Flip for Function

The clearest difference is update cadence: King at every 2 months against Flip for Function's every 13 months. King also leads on iOS requirement (9.0 vs 15.0). Flip for Function's advantage is device support (3 vs 1). On price, ads and in-app purchases there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

King ships an update every 2 months, Flip for Function every 13 months. The most recent releases landed on October 2, 2026 and October 12, 2026 respectively.

## The numbers

| Metric | King | Flip for Function |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (2 ratings)](https://appshunter.io/ios/app/king-devick-test/id1033607954/reviews)** | — |
| Number of ratings | **2** | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 2 months** | Every 13 months |
| Monetization | Free | — |
| Size | 243 MB | 47 MB |
| Requires iOS | **9.0** | 15.0 |
| Devices | iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [King-Devick Test, LLC](https://appshunter.io/developer/424793545) | [Flip for Function, PLLC](https://appshunter.io/developer/1784562917) |

## What reviewers say

### King

[App page](https://appshunter.io/ios/app/king-devick-test/id1033607954)

This app provides a quick and objective sideline concussion screening test for athletes. It helps identify potential concussions by assessing eye movements, attention, and concentration through a simple number-reading exercise. Requires an existing King-Devick Online account.

**Highlights:** Objective sideline concussion screening, Assess eye movements and attention, Administer baseline and post-injury tests, Works offline, Suitable for ages 5+

**Features:** macOS Compatibility

**In-app purchases:** none


### Flip for Function

[App page](https://appshunter.io/ios/app/flip-for-function/id6739267164)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is King free?

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

### Is Flip for Function free?

Flip for Function is free to download, with no in-app purchases.

### Do King or Flip for Function have ads?

Neither King nor Flip for Function shows ads.

### Which is updated more often, King or Flip for Function?

King ships an update every 2 months, and Flip for Function every 13 months. Most recently, King was updated on October 2, 2026 and Flip for Function on October 12, 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.*