To access the SVD App you must force close it and then reopen it. To do so, you must remove the app from the "multitasking", also known as "background" or "recent apps".
Here's how to do it.
On iOS:
To access the background feature, swipe diagonally from one of the lower corners to the center of the screen. Once you see all the apps running in the background, just slide the SVD app window up.
In models like the SE with a physical button, press the home button twice. Once you see all the apps running in the background, just slide the SVD app window up.
If you have an iPhone X:
To close the app in the background you have to hold down on one of the screen and slide it up when the “-” sign appears in the corner.
On Android:
Most models have a specific physical button to access the list of recently used applications.
If your phone doesn't have one, try holding down the home button.
Once you access the list, you can close the SVD App by dragging it to the side or clicking on the "x" icon.