Turning on developer options on Galaxy S4

How do you turn on developer options (debug, adb, etc) for the Samsung Galaxy S4?

How do I enable Samsung developer options?

Enable developer options and USB debugging On Android 4.1 and lower, the Developer options screen is available by default. On Android 4.2 and higher, you must enable this screen. To enable developer options, tap the Build Number option 7 times.

Go to – Settings > About phone.
Then move on to Build number option
Tap on Build number repeatedly 7 times.
This is enough.
After touching 7th time you will see a message that, “You are now a developer”.

Now you'll have developer options under the System heading, from where you can enable USB Debugging etc.

Also make sure you're running the latest tools on your computer, as 4.2.2 onwards you have to verify the RSA key for ADB. This is not available unless you are running the latest version of ADT, and your device will appear offline when connected if you're using an older version.

References: Android Central, Haptic Antics