We are going to develop an app that allows a video conference to be scheduled. Person 1 will schedule a time based on the availability of Person 2.
What I'd like to happen is when Person 1 opens the application on the scheduled date, the first screen would show that s/he has an upcoming conference call very soon (with a countdown timer) and when the countdown timer ends, it will show something like "Start Conference Now", which, when the user clicks, will start connecting Person 1 to Person 2.
Let's say Person 1 scheduled an appointment next Tuesday at 10AM. What is the best way to alert this person that s/he should open the application at 10AM (or few minutes before that)? Should it be an SMS? A Push Notification?