Yes. On the Web: To pay the total amount owed on all accounts, click the Pay Now button in the upper right corner of the screen, or the Make Payment button on the home page. You can also make a payment to a single account or partial payments to all accounts by clicking on the Billing & Payments button.  It will allow you to check the accounts to be paid and change the amount for each account by clicking on Other Amount.  After entering the amounts to be paid, click the Pay Now button.
On the App: Tap the Bill, Pay & Reading icon.  If paying the total amount due, tap the Pay button.  If paying a partial payment, tap the Pay Partial Amount, tap on the account and adjust the Pay Amount.