From time to time, a virtual queue—accessible via the My Disney Experience app—may be used for select attractions or experiences.  Usually, the Virtual Queue is used for the newest, most popular attractions.
When a virtual queue is in place, you can request to enjoy that attraction or experience later in the day, so you can enjoy other experiences while you wait. When the virtual queue is in place, a standby queue will not be available, and Guests must use the My Disney Experience app to enter the attraction or experience.
Log into the My Disney Experience app just prior to 7:00am on the morning of your visit to that park.
Ensure everyone in your group is connected to your account through the Friends and Family list, and that they each have valid admission to that park for today.
You can select everyone in your group to enroll in the Virtual Queue as soon as 7:00am hits.
Your boarding group will be called for that attraction later in the day, when you can go back and enjoy the experience!
Boarding Groups for the Virtual Queue fill up in SECONDS.  Waiting much longer after 7:00am means you may not get into the queue.
Some attractions have an additional opportunity to join the virtual queue later in the day.  If you missed the 7:00am opening, look at My Disney Experience for other times throughout the day when they may be accepting more Virtual Queue enrolments.