Originally Posted by tommykwan222
sorry that I cannot find it inside "Developer options", can you tell me where is it ?
You have to choose Settings -> Info and click 7 times where there's written yout build number (it should be the second-last line).
After that, you will find in the application list one that is called Dev Tools, its icon is a couple of gears.
Click it and then choose Developer options: it should be the third option.
I think it should be the same no matter which ROM you have (I have SlimKat 4.4.4 build 6.2 weekly).
I don't remember if you need to root your device before, but I don't think so.
Devices: HTC One
Samsung GALAXY Note 10.1 (2014 edition)
HTC 7 Pro (Wi-Fi/game station home usage)
HTC Touch Cruise (retired)
Nokia N73 (retired)