This prank is hilarious it will make your friends phone go crazy but it dose not do any real damage so completely safe
Step 1: Developer Option
Go to settings then scroll down to developers option click it.
Then activate the developers option.
Step 2: Real Thing
Scroll down below drawing there will be a option show surface updates click the check box and then relax its done. Screen will go crazy make it look like a virus
Step 3: Safe
Developer option is made maily for programmers for testing device just turn off developer option to bring back device to normal
Step 4: Check This Out
Wanna make a cool spy boat