Surprised!ReactionTimeChecker? vs PK
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Surprised!ReactionTimeChecker?
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.
- Sudden fear image display
- Captures user's surprised photo
- Sound effects in silent mode
- Requires camera permission
- Prank and surprise friends
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This app " Surprised! Reaction Time Checker?” is not an app to measure reflexes. When playing in a game that measures reflexes, it suddenly displays a fear image, and it is a surprise app to take a picture of the player of that moment. Surprise your friends, lovers and family and get their photos! You may get a photo of the surprised look of a yearning person ... *This application has sound effects even in silent mode. *In order to use the camera function to take photos, you need "Camera" and "Add photos only" permission to use this app. *Please check the photos taken with the "Photos" app. *Shaking the device violently can cause photos to be blurred. *Be aware that the player is surprised and may break the device. *Even if the user uses this game, the user or a third party other than the user, equipment, or even if there is a case where damage or a failure has occurred in human relations, we do not have any responsibility. *If you are using iOS 14.5 or later, a dialog asking for tracking permission will be displayed at the first startup. Production: NSC, K.K. If you have any problems or requests, please check the contents of the “Contact Us” page on our website and send us an e-mail. Click here for “Contact Us”: https://www.nscnet.jp/inquiry.html
PK
Create a paranormal illusion by magically moving permanent ink on your mobile screen. Spectators choose ink placement and color, and you control the movement remotely or with hand gestures. Offers multiple finales and can integrate with other magic apps for advanced effects.
- Spectator-chosen ink placement
- Customizable marker colors and designs
- Remote control and hand-gesture recognition
- Multiple powerful finales
- Offline functionality
- Integration with other magic apps
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With PK-Ink App, you can magically move permanent ink drawn on your mobile screen! Key Features • The spectator chooses the exact spot where the ink will appear. • The spectator can select from a variety of marker colors or designs — or you can upload your own drawings. • Move the drawing without touching the phone, using remote control or advanced hand-gesture recognition. Multiple gesture options included: pinch, index finger pointing, open-hand (5 fingers), and more — all highly reliable. • Multiple powerful finales: the spectator will be unable to erase the ink they just saw move. You start clean and end clean. • No internet connection required (unless you use integrations). • Integrate your favorite magic apps with an Ouija-style effect: Imagine the spectator searching for a word in apps like Inject or Elips, and the ink begins to move toward each letter or number — triggered by hand gestures, volume buttons, or fully automatic mode, gliding smoothly across the entire alphabet. Use this as a paranormal illusion with the built-in video animation feature, or as a psychic/magical effect by moving the ink across any Ouija board image you’ve downloaded. • Video instructions available in English and Spanish. • Extremely easy to use — no complex setup or configuration required.
Screenshots
Verdict
The clearest difference is price: Surprised!ReactionTimeChecker? at Free against PK's $99.99. Surprised!ReactionTimeChecker? also leads on device support (3 vs 1). PK's advantage is ads (none vs shown) and update cadence (every 2 months vs every 6 months). On review sentiment, in-app purchases and iOS requirement there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Surprised!ReactionTimeChecker? is free to download; PK costs $99.99 up front. Neither carries in-app purchases, so what you see is what you pay.
Surprised!ReactionTimeChecker? ships an update every 6 months, PK every 2 months. The most recent releases landed on October 23, 2026 and November 3, 2026 respectively.
| Parameter | Surprised!ReactionTimeChecker? | PK |
|---|---|---|
| Price | Free — better | $99.99 |
| Rating | — | 5.0 (2 ratings) — better |
| Positive reviews | 100.0% of reviews | 100.0% of reviews |
| Number of ratings | — | 2 — better |
| Update frequency | Every 6 months | Every 2 months — better |
| Ads | Yes | No — better |
| In-app purchases | No | No |
| Monetization | Ad-supported — better | Paid |
| Devices | iPhone, iPad, iPod — better | iPhone |
| Requires iOS | 15.6 — better | 16.0 |
| Further details — not scored | ||
| Size | 24 MB | 16 MB |
| Age rating | 12+ | 4+ |
| Developer | NSC, K.K. | Nelson Suarez Arteaga |
Customer experience
Surprised!ReactionTimeChecker?
PK
In-app purchases
Surprised!ReactionTimeChecker?
No in-app purchases
PK
No in-app purchases
Questions
Is Surprised!ReactionTimeChecker? free?
Is PK free?
Do Surprised!ReactionTimeChecker? or PK have ads?
Which is updated more often, Surprised!ReactionTimeChecker? or PK?
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