Note that if you stick with the Rule instead of the app, you might want to make a small modification to your actions. Right now, your light will turn off 30 minutes after any time it's turned on. If you turn it on at 1 PM, turn it off at 1:20, then turn it back on at 1:29, it will still turn off at 1:30, even though it has only been on for 1 minute and not 30 (and it will also turn off at 1:59 if still on, and likewise for any "on" action you do at any time--these future, delayed "off" actions will pile up and still run as originally scheduled regardless of what you do in the meantime).
The solution if you use a delay and don't want this behavior is to explicitly cancel it, with a common pattern being something like:
Triggers: Front Door turns *changed*
Actions:
IF (Front Door is on) THEN
Delay 0:30:00 (cancelable)
Off: Front Door
ELSE
Cancel Delayed Actions
END-IF
