iPhone Screenshots


Do you think you have cat-like reflexes? Use Kneejerk and find out! See how
your reaction and response times change based on how youre feeling, your age,
gender, or even location.

KneeJerk is a suite of reflex testing games. There are three types of games that test
your skills: Reaction, Whack-A-Yak, and Stop the Clock.

- Reaction is a pure reflex timing game. An event is triggered either using visual, audio,
or haptic cues. Your timed as to how fast you can react.
- Whack-A-Yak is a game testing your visual processing and coordination skills. A Yak
appears somewhere among a herd of animals. How fast can you find and hit a bunch of Yaks?
- Stop the Clock is a timing game. Watch the counter go down and stop the clock as
close to 0.000 as possible.

The game can optionally submit your profile (Age, Gender, Zip, and Mental State) to a statistics
website where you can see how you perform amongst your age group, neighbors, gender and
alertness level.

What’s New

Version 1.5

- Added an Analog mode to "Stop the Clock"
- Added GameCenter
- Other small tweaks and improvements

Ratings and Reviews

4.3 out of 5
7 Ratings
7 Ratings
Older old guy ,

Great app

This is great for testing my reflexes under various states of tiredness, and loads of fun!

Carringtonsmith ,

Whack a yak

This games kinda scares me a little it's hard but lots of FUNNN!!!

Artemesia27 ,


Lots of mindless fun-addictive (:


Michael Suarez
2 MB
Requires iOS 3.2.2 or later. Compatible with iPhone, iPad, and iPod touch.
Age Rating
Rated 4+
© Daedalus onWing


  • Game Center

    Challenge friends and check leaderboards and achievements.

  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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