Two prank styles for your choice:

★ Optical Illusion Prank:

*Step 1: Turn phone volume to max, then click the start button,
You will be asked to set a jumpscare timer.

*Step 2: Give someone your phone and tell him to stare at the optical illusion to see something cool.

*Step 3: The jumpscare will show up at the time you have set

★ Fake Virus infection Prank:

*Step 1: Turn phone volume to max, then click the start button,
Your phone will show a fake virus infection message, giving an option to remove by clicking "OK" or "Cancel" to keep it.

*Step 2: Give your phone to someone and tell him you went to a website and found this message or perhaps you
just saw it after you installed an app, and pretend it's an android virus. act clueless or scared and ask for his advice.

*Step 3: Once he clicks "OK" or "Cancel" a jumpscare will show up, and he will go out of his mind!

Expect reaction from people such as Ahhh! or Holyshit if you use this app. The app's pranks were tested and proven as scary, so this is a good scary prank if you want a scary jumpscare to surprise your friends.
They are indeed funny pranks in every situation, for example if you want to surpirse someone on april fools day, use this as a aprils fools prank.