When can I tell Siri to 'Remind me about this'? Sometimes when I tell Siri "Remind me about this" or "Remind me about this when I leave/arrive/get home/work/car" she replies:


  OK, just tell me what you want to be reminded about.


And other times, depending on the app, she adds a reminder to my reminders list. Is there any to know if telling Siri "Remind me about this" will result in a reminder being creating without trying it first on a specific screen?
As far as I can tell there is no way to tell if you are using a single device. However if you have more than one device that is Handoff enabled then you can be reasonably certain that if a screen within an app makes Handoff visible to another device then you can tell Siri to "Remind me about this" and a reminder will be created.