Haha I doubt this is the answer, but it fits rather amusingly.
You are
Smartphone system update notifications!
You cannot accurately predict my arrival.
I seem to appear randomly out of nowhere.
Nobody knows when the update notification will appear!
Without a word, I compel you into action.
My demands upon you are always the same.
No words necessary, just that darn symbol at the top of your notification bar that sits there FOREVER. The demand, obviously, is that you perform your system update.
Choose to ignore me, and I'll annoy you.
You have a strong desire to obey my will.
Seriously, it's super annoying. At least on my phone, I can't swipe it away or clear it from my notifications unless I perform the actual update.
I do visit some people more than others,
But all will deal with me at some point.
Some phones probably require system updates more than others, but anybody with a smartphone will need to do it at some point. Although maybe iPhones do it automatically, I wouldn't know.
Once obeyed, I usually leave for awhile,
But sometimes I reappear nearby for more.
After you actually perform the update, the notification disappears. Alas, I am unable to make the last line fit, specifically the "nearby" part.