On my GS3 the options for auto-locking range from "immediately" to "30 minutes". Suppose I wanted the auto-lock to happen only after 1 hour - is there any way to do this?
There are probably multiple solutions. The one coming to my mind again involves an app named Tasker, which is the most flexible automation app on Android. An idea would be to have it start a timer whenever the screen is switched off, which is "blanked" whenever the screen is turned on. Have the key guard turned off initially (i.e. no lock takes place), and turn it on when the timer's up (lock).