# Surprised!ReactionTimeChecker? vs Mental Dice

The clearest difference is price: Surprised!ReactionTimeChecker? at Free against Mental Dice's $3.99. Surprised!ReactionTimeChecker? also leads on update cadence (every 6 months vs every 26 months) and device support (3 vs 1). Mental Dice's advantage is ads (none vs shown). On in-app purchases and iOS requirement there is nothing between them.

Surprised!ReactionTimeChecker? is free to download; Mental Dice costs $3.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Surprised!ReactionTimeChecker? ships an update every 6 months, Mental Dice every 26 months. The most recent releases landed on June 1, 2026 and September 21, 2026 respectively.

## The numbers

| Metric | Surprised!ReactionTimeChecker? | Mental Dice |
| --- | --- | --- |
| Price | **Free** | $3.99 |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | No | No |
| Ads | Yes | **No** |
| Update frequency | **Every 6 months** | Every 26 months |
| Monetization | Ad-supported | — |
| Size | 24 MB | 1 MB |
| Requires iOS | **15.6** | 16.0 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 12+ | 17+ |
| Developer | [NSC, K.K.](https://appshunter.io/developer/501890400) | [matsumoto yuuki](https://appshunter.io/developer/984437953) |

## What reviewers say

### Surprised!ReactionTimeChecker?

[App page](https://appshunter.io/ios/app/surprisedreactiontimechecker/id553393907)

This app captures photos of users when they are startled by sudden fear images. It's designed for playful pranks to surprise friends and family, documenting their genuine reactions. Note that it utilizes sound effects even in silent mode and requires camera permissions.

**Highlights:** Sudden fear image display, Captures user's surprised photo, Sound effects in silent mode, Requires camera permission, Prank and surprise friends

**In-app purchases:** none


### Mental Dice

[App page](https://appshunter.io/ios/app/mental-dice/id1580340447)

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

**In-app purchases:** none


## Frequently asked questions

### Is Surprised!ReactionTimeChecker? free?

Surprised!ReactionTimeChecker? is free to download, with no in-app purchases.

### Is Mental Dice free?

Mental Dice costs $3.99, with no in-app purchases.

### Do Surprised!ReactionTimeChecker? or Mental Dice have ads?

Surprised!ReactionTimeChecker? shows ads; Mental Dice does not.

### Which is updated more often, Surprised!ReactionTimeChecker? or Mental Dice?

Surprised!ReactionTimeChecker? ships an update every 6 months, and Mental Dice every 26 months. Most recently, Surprised!ReactionTimeChecker? was updated on June 1, 2026 and Mental Dice on September 21, 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.*