I've had my apex for 2 years and didnt realize it now has the heartbeat feature. I know it's been discussed in the forum (slightly) but given how important it is I thought I would reiterate. After all, if it saves 1 tank, it was worth the time
I read that it pings every 10 minutes to see if your apex is up. I have yet to test this, however.
For those of you who havent updated in awhile, this could be a great reason to do so.
Here's a vid on it's setup: