For this:

1. In your phone settings, turn on vibration.

2. Launch the application

3. Place the phone with the screen facing up on a flat, smooth, inclined object, such as a book or board. The tilt of the board should be such that the phone slides along it only when it vibrates.

4. Touch the screen once. The oval at the top of the screen should change color from red to yellow, which means the phone is ready to start.

5. Clap your hands loudly. The phone will begin to vibrate and slide down the board.

6. When the phone reaches the bottom of the board, tap the screen once and the phone will stop vibrating. The number in the oval will show the time taken. If you tap the screen again, this number will reset to zero and the phone will be ready for the next run.

In the same way, you can slide other phones down the board and compare the time.

If the width of the board allows, you can slide several phones down it at the same time. Prepare all phones as described in steps 1, 2, 3 and 4 above and clap your hands to start the race.

A slider at the top of the screen allows you to set the volume threshold at which your phone will start vibrate. The further to the right the slider is, the lower this threshold is.

The button in the upper right corner allows you to select the background color.

You can change the emoji by tapping the text field at the bottom of the screen. You should enter one character in this field - a letter, number or emoji, after which this character will appear in the center of the screen. The character must be entered without spaces.

If you enter multiple characters into the text field, they will not appear in the center of the screen.

If you do not turn off vibration by touching the screen, it will turn off automatically after 5 minutes.

Do not use this application if there is a risk of dropping or damaging your phone.