To view your virtual cards, tap on the "vCards" icon at the bottom of the screen in the main nav bar.
You'll be brought to the virtual cards listing page. On this page, you'll be able to see all your card details, including the remaining balance. For additional details, tap on the card you want to view.
You can view any transaction made against that card by tapping on the "View Card Transactions" link text. This will bring you to the "Transactions" tab pre-filtered for that card.