The app can synchronize your folder and files in the background,

so they are completely up-to-date when you need to view them. 

Under this setting you can select which connectivity stage this

synchronization should happen:

When you press the field you will get the following options:

“Only on Wi-Fi”
Synchronize when you are connected to a Wi-Fi access point

Synchronize when you are connected to any connection. 

Please note there might be additional cost if you are using cellular data

This will turn off the automatic synchronization.

You can always synchronize on list pull-down.