These instructions apply to phones running Android 7 and later.
Scroll down until you locate theBuild numbersection.
Tap theBuild numberuntil you see a message that saysYou are now a developer!

Jeremy Laukkonen
You likely will not receive any feedback after the first few taps.
Before it’s possible for you to complete the process, your phone may ask you for your PIN.
However, activating and changing various developer options without understanding what you’re doing can have unwanted effects.

Navigate toSettings>Developer options.
You may have to search in parameters to find it.
You will also have the ability to activate a variety of advanced options.

Tap the “On” toggle at the top of the Developer options screen.
It should change toOff.
What Is Android Developer Mode, and Who Needs It?

Developer mode is designed primarily for Android developers.
It reveals options and parameters that developers need access to when testing new apps.
FAQ
Tomake Android faster, use developer options to shorten the system animation scale.

Jeremy Laukkonen
Go toDeveloper Optionsand set theWindow animation scale,Transition animation scale, andAnimator duration scaleto.5x.
On Samsungs and some older devices, press theVolume downbutton while the logo is on the screen.
To exit safe mode, reboot the gear.
Toturn on USB debugging mode on Android, go toDeveloper Optionsand tap theUSB debuggingtoggle switch.