I have 2 devices: one with Android 4.2.1 (Emotion UI 1.6), one with Android 5.1.
Android 4 device has an option in "developers" settings to always keep screen turned on while charging. Android 5 device seems not have "developers" settings at all, and I couldn't find such an option to keep screen turned on while charging anywhere.
Could I somehow tell my Android 5.1 device not to turn off the screen after timeout, when charger is plugged?