You can quickly access the first three cards of your cards list through the mobile-pocket widget on your iPhone. To enable the mobile-pocket widget press the "home screen" until you are in the editing mode. Then click on the "+"-symbol in the top right corner of the screen and search for "mobile-pocket". Now you can pick a widget and "add" it. To edit the displayed cards hold the "widget" and select "edit widget".
If you tap on a card within the widget, this will open directly in mobile-pocket.